According to Jony Ive, engineering revisions to each product is not a drop in some new chips and be done with it. If that was the case, we would have MacBook Pro's with Coffee Lake chips already.Huh? Pretty much all those things (except for maybe HomePod) would get updated every year, or almost every year.
They will not delete all the K models. That would be a very foolish business decision, as they are extremely popular upgrades that generate increased revenue. The problem with the iMac Pro is that it is way over the budget of many at iMac customers.
Most people aren’t going to jump an 8-core iMac Pro just because a 6-core i7 is not available.
The chin is too big, which makes the screen quite high. Not the best for ergonomics.
These things take time to test and engineer. Work on the iPhone X started back as far as 2014 if you take into account Face ID; and they had to work hard to engineer the Super OLED. The iMac Pro wasn't a one year decision either. I'm sure to create a Plus variant of the iPhone X is not gonna be easy because they got the hard work done with the X.
Can you manufacturer a 6.5 inch all super OLED phone at scale? Can you make it convenient to hold, can we get enough OLED panels for it. What are the performance criteria's for the SoC?
They don't have engineers in great abundance they can just allocate to these projects. Most times, its the same team that did both Mac and iPad and HomePod. Thats a lot of work for a still relatively small group of people.