In order to assist those who would like to better predict Apple's upgrade paths for its mobile lineup, I am offering some comments and links. Please feel free to add information or correct errors.
Starting with Kaby Lake, Intel is offering three (or four if you distinguish by TDP) classes of CPUs: H (45-35W), U (28-15W), U (15W), and Y (4.5W). These processors are suitable for the MBP 15", MBP 13", MBA, and MB, respectively.
Below is a chart from another site which shows Intel's general release schedule:
Unfortunately the chart is only a general platform release schedule and misrepresents specific CPU and SOC releases. For example, Kaby Lake H-Processors are going to be released but only as 2+(GT)3e and 4+(GT)2. Thus there is no Kaby Lake release slated for the 4+(GT)3e that Apple prefers for its MBP 15".
A more detailed chart of Intel's planned release schedule from the same site is below:
This chart is more accurate and reflects the anticipated quarterly release dates, including more specific CPU and SOC releases. However, this is only what Intel anticipated releasing. Actual release dates for specific CPUs and SOCs are found on the Skylake Wiki.
Before commenting on processors and SOCs, it is important to understand some of the nomenclature Intel uses with regard to GPUs and SOCs. For Skylake, and presumably Kaby Lake, Intel uses the label GT2 to denote Intel integrated GPUs (called Intel HD), GT3e to denote Iris GPUs, and GT4e to denote Iris Pro GPUs. The "e" denotes embedded DRAM cache which adds (64MB for Iris / 128MB for Iris Pro) on package EDRAM memory to boost GPU performance.
Now that we have that out of the way, let's break down the charts and parts.
MB - Y Processors
Annual updates: Skylake released and in current lineup. Kaby Lake released in Q3 2016. Cannon Lake releases in Q4 2017.
MBA (if continued) - U (15W) Processors
Annual updates: Skylake 2+(GT)2 released but not in current lineup; Kaby Lake released in Q3 2016. Cannon Lake releases in Q4 2017.
MBP 13" - U (15-28W) Processors
Annual updates (?): Skylake SOC 2+(GT)3e released but not in current lineup. Kaby Lake 2+(GT)3e releases in Q1 2017. Coffee Lake 2+(GT)3e releases in Q2 2018.
MBP 15" - H Processors
18 month updates (?): Skylake SOC 4+(GT)4e has not released (due to Intel?) and is not in current lineup. "Kaby Lake" SOC has been renamed "Coffee Lake" and releases in Q2 2018.
Unfortunately, as can be seen, after the 4+4e Skylake release which is due immanently, there is no other quad-core SOC update suitable for the MBP 15" until Q2 2018, when Coffee Lake is introduced. A quick note on Coffee Lake: Coffee Lake is simply the Cannon Lake architecture on a 14nm node. Apparently Intel will be unable to achieve enough yield at 10nm to produce a suitable quantity of the more complex SOCs, so Intel is going to continue to use its 14nm process for the more complex SOCs with Iris (GT3e) and Iris Pro (GT4e) GPUs while the less complex production of standalone CPUs which can be paired with Intel iGPUs or Nvidia or AMD dGPUs will progress to the 10nm node. In sum, there is one architecture (Kaby Lake) which will be produced on two nodes: 10nm (Kaby Lake) and 14nm (Coffee Lake). It is hoped that the architectural improvements (called Ice Lake) which will follow Kaby Lake will all be produced at the 10nm node.
It is also worth noting that there are indeed CPU-GPU combinations which Apple has chosen not to utilize. For example, many MR members point to the inclusion of Skylake CPUs in current systems produced by companies such as Dell. As is shown in the chart above, the Skylake 4+GT2 combination has been available and is being utilized by companies such as Dell. Likewise, systems makers which choose to use only integrated GPUs from Intel or only discrete GPUs from Nvidia or AMD will have access to quad-core Kaby Lake CPUs starting Q4 2016 when presumably Apple will only just be receiving and shipping Skylake SOCs in its lineup.
One other down note: Coffee Lake is set to introduce hexa-core (6 core) CPUs into mainstream mobile computing; however, hexa-cores will only be paired with Intel's GT2 GPUs or with a discrete GPU from Nvidia or AMD. There are no known options for a Coffee Lake 6+(GT)4e SOC which would be used by Apple, so there is little hope for a six core system from Apple in the near future.
Starting with Kaby Lake, Intel is offering three (or four if you distinguish by TDP) classes of CPUs: H (45-35W), U (28-15W), U (15W), and Y (4.5W). These processors are suitable for the MBP 15", MBP 13", MBA, and MB, respectively.
Below is a chart from another site which shows Intel's general release schedule:
Unfortunately the chart is only a general platform release schedule and misrepresents specific CPU and SOC releases. For example, Kaby Lake H-Processors are going to be released but only as 2+(GT)3e and 4+(GT)2. Thus there is no Kaby Lake release slated for the 4+(GT)3e that Apple prefers for its MBP 15".
A more detailed chart of Intel's planned release schedule from the same site is below:
This chart is more accurate and reflects the anticipated quarterly release dates, including more specific CPU and SOC releases. However, this is only what Intel anticipated releasing. Actual release dates for specific CPUs and SOCs are found on the Skylake Wiki.
Before commenting on processors and SOCs, it is important to understand some of the nomenclature Intel uses with regard to GPUs and SOCs. For Skylake, and presumably Kaby Lake, Intel uses the label GT2 to denote Intel integrated GPUs (called Intel HD), GT3e to denote Iris GPUs, and GT4e to denote Iris Pro GPUs. The "e" denotes embedded DRAM cache which adds (64MB for Iris / 128MB for Iris Pro) on package EDRAM memory to boost GPU performance.
Now that we have that out of the way, let's break down the charts and parts.
MB - Y Processors
Annual updates: Skylake released and in current lineup. Kaby Lake released in Q3 2016. Cannon Lake releases in Q4 2017.
MBA (if continued) - U (15W) Processors
Annual updates: Skylake 2+(GT)2 released but not in current lineup; Kaby Lake released in Q3 2016. Cannon Lake releases in Q4 2017.
MBP 13" - U (15-28W) Processors
Annual updates (?): Skylake SOC 2+(GT)3e released but not in current lineup. Kaby Lake 2+(GT)3e releases in Q1 2017. Coffee Lake 2+(GT)3e releases in Q2 2018.
MBP 15" - H Processors
18 month updates (?): Skylake SOC 4+(GT)4e has not released (due to Intel?) and is not in current lineup. "Kaby Lake" SOC has been renamed "Coffee Lake" and releases in Q2 2018.
Unfortunately, as can be seen, after the 4+4e Skylake release which is due immanently, there is no other quad-core SOC update suitable for the MBP 15" until Q2 2018, when Coffee Lake is introduced. A quick note on Coffee Lake: Coffee Lake is simply the Cannon Lake architecture on a 14nm node. Apparently Intel will be unable to achieve enough yield at 10nm to produce a suitable quantity of the more complex SOCs, so Intel is going to continue to use its 14nm process for the more complex SOCs with Iris (GT3e) and Iris Pro (GT4e) GPUs while the less complex production of standalone CPUs which can be paired with Intel iGPUs or Nvidia or AMD dGPUs will progress to the 10nm node. In sum, there is one architecture (Kaby Lake) which will be produced on two nodes: 10nm (Kaby Lake) and 14nm (Coffee Lake). It is hoped that the architectural improvements (called Ice Lake) which will follow Kaby Lake will all be produced at the 10nm node.
It is also worth noting that there are indeed CPU-GPU combinations which Apple has chosen not to utilize. For example, many MR members point to the inclusion of Skylake CPUs in current systems produced by companies such as Dell. As is shown in the chart above, the Skylake 4+GT2 combination has been available and is being utilized by companies such as Dell. Likewise, systems makers which choose to use only integrated GPUs from Intel or only discrete GPUs from Nvidia or AMD will have access to quad-core Kaby Lake CPUs starting Q4 2016 when presumably Apple will only just be receiving and shipping Skylake SOCs in its lineup.
One other down note: Coffee Lake is set to introduce hexa-core (6 core) CPUs into mainstream mobile computing; however, hexa-cores will only be paired with Intel's GT2 GPUs or with a discrete GPU from Nvidia or AMD. There are no known options for a Coffee Lake 6+(GT)4e SOC which would be used by Apple, so there is little hope for a six core system from Apple in the near future.