I suspect Apple got scared with the performance of the new NVIDIA graphics chips and realised that the M2 Mac Pro was not going to be up to cheddar. I suspect putting an AMD Radeon 7000 series in a 2019 Mac Pro was going to give much better graphics performance and more expandability so they decided to hold off. The thing is that so many pro apps are dependant now on Graphics performance so unless it is a generation quicker than the 2019 Mac Pro + internal GPU then who would buy it? Also Thunderbolt 5 is going to have much better support for full bandwidth eGPUs so again you would be looking at comparing a cheaper x86 laptop with powerful eGPU against a Mac Pro or MacBook Pro without eGPU support.
Herein lies the problem which was always going to bite them in the ass. They bit off a lot saying they can take on Intel, AMD and Nvidia with Apple Silicon. Apple Silicon is snappy at OS tasks however it's still no match for a dedicated GPU. The new Apple TV is slower graphic performance wise than a PS4 from 10 years ago. Apple needs to fix eGPU support for M2 or M3 and then they may have a suitable product for the Apple Silicon Mac Pro.
Personally I have decided to hold off on migrating to Apple Silicon until the Mac Pro is out. I have too many hardware dependancies that I can't migrate yet - LTFS, SAS, AMD GPU. It's my opinion that all the other Macs on Apple Silicon are just test platforms until the Mac Pro comes out and so far Apple are failing because it's way behind schedule.
