I'm not following. Exactly when is the last time Apple released an iMac with an intel processor that was just released a month or two prior? They always go for the current, entrenched generation chips, not the 'just released' ones.
Kaby Lake S-Series was released on January 3, 2017, which include all K and non-K variants (18 - 7xx0 SKUs), according to WikiChip, and Apple released the 2017 iMacs on June 5, 2017. So from announcement to release in a macOS-based computer, it took 5 months (CW1-CW23). So, 22 calendar weeks from announced to in a shipping product. It took more than a couple of months, but it was not a year or two later.
Coffee Lake 45w H-Series and 28w U-Series were released on announced and launched on April 2nd, 2018 and Apple released the
2018 13" and 15" MacBook Pros containing those CPUs on July 12, 2018 (CW14-CW24). So
ten (10) calendar weeks from announced to in a shipping product.
At this point, Apple is waiting on Intel...the majority of Intel's Coffee Lake S-Series launched in April of 2018, including the Core i5-8500B and Core i7-8700B, which means Apple had them in shipping products in (CW-14-CW44), which was a little under 7 months.
Coffee Lake R-Series (Refresh) - Three (3) 9000-Series CPUs were released on October 19, 2018. Six (6) additional 9000-Series CPUs were released on January 7th, 2019. Nine additional 9000-Series CPUs have yet to announced and released as of today. Should Intel announce and released them in April of 2019 as they have done with CPUs in the past, I do not think it is out of the question for Apple to release an updated iMac as WWDC, although they may not ship until the end of the month, depending on supplies.
I see the 8000-Series going into the 21.5" iMac and the 9000-Series going into the 27" iMac, with a possible overlap of 1 or 2 8000-Series CPUs in the 27" at the lower end. I think the biggest hold up now is the Navi 7nm GPUs. It is clear the Vega 16 and Vega 20 were late or yields were not as expected. Apple is ready to move on from Vega 56 and Vega 64 and is not going to put those or the RX590 in the iMacs just to get something out the door. My guess is that they are waiting for an announcement by AMD (Computex Taipei 2019 is in May) and hopefully AMD is ready for mass manufacturing.
My point was that Apple is not nearly behind the times as people like to joke about in these forums. Apple just is not on a Dell, HP, Lenovo schedule of announce and then wait for CPUs to show up, hoping that Intel doesn't run into a problem. It makes them look cutting edge, but they weren't shipping coffee Lake H-Series laptops any sooner than Apple, it just looked like they were.
Apple is not going to ship until Intel has filled up the product portfolio for a given CPU generation. Case in point, Intel announced the Core i7-8700K, i7-8700, i5-8600K and i5-8400 in September of 2017, and launched in October of 2017. IIRC, laying your hands on the i7-8700K was not easy, they were not plentiful. None of the initial CL-S were plentiful, and Intel did not finish filling out the CPU lineup until April of 2018. Assume another thirty days from launch to in the OEM's hand and that's November, less than 3 weeks before Black Friday. First, there were not enough CPUs for the different tiers of iMacs and then most likely not enough CPUs to keep a steady supply for sale through the holiday. It would have been a mess for Apple. Remember, Intel prioritized the Core i5-8250U and Core i7-8350U CPUs for their PC OEMs, because laptops sell and this was a NEW quad-core CPU, which guaranteed Dell, HP and Lenovo a bang up holiday season. Anyways, just my 2¢.
