Kinda foolish to release it now, should've waited for the release of Navi GPUs, especially since the GPU isn't upgradable in that one.
Typical of Apple, they always had top specs except GPU in their machines.
And just when is AMD supposed to ship new Navi GPUs? Apple has been taking heat for quite a while over the lack of iMac updates, and it clearly shows that they had to regroup on the GPU choices at some point.
I read that 7nm Navi will be announced in May, but that was right after I read another article that said they would be pushed out to October or November, so who knows how long Apple might have to wait for AMD to be up and running with sufficient numbers to put in new iMacs. Its fairly obvious that the GPUs choices for the updated iMac are more like a forced confession, along with the bottom two tiers of the 27" iMac using 8th Generation CPUs instead of 9th Gen.
Just looking at the ARK - Intel has still not released both the Core i5-9500 and Core i5-9600 that Apple would have put in the $1799 and $1999 iMacs. I can accept, and in fact predicated, that 8th Gen would go in the 21.5". I even predicted that Apple might end up having to use 8th Gen in the 27" if Intel did not have CPUs announced and launched in time. I think Apple waited until it was clear Intel and AMD could not give them what they needed and had to punt. Hell, Intel is still having supply issues with 14nm CPUs and is predicted to continue having issues for the rest of the year.
Blame Apple all you want, but I am not. AMD is focused on Ryzen and Threadripper, and they should be. However, you cannot blame Apple for wanting to shift to in-house GPUs at some point.
On the other side, Intel is still battling its 10nm woes while 14nm production suffers despite what has been record demand. Anyone waiting for Sunny Cove, Ice Lake, et al and thinks Intel will have volume production by the end of Q3/2019 should refrain from ever stepping foot in a casino.
The frustration on these forums towards the lack of an iMac revision was palpable in November after the iPad Pro/mini/Air event. I do not think Apple had the luxury of waiting until WWDC or a fall event at this point and decided that they had to get something out the door before the torches and pitchforks were outside the spaceship.