MartinMBP20 wrote:
I have to do a lot of asumptions right now. I will be able to play Diablo 4 regardless if Blizzard provides a Mac release or a Windows only release and we have to switch to Windows via bootcamp
Bootcamp is not available on Apple silicon Macs. The only way to run Windows on an M2 Mac would be through a virtualization option like Parallels. However, that would only let you run the ARM version of Windows, and it's impossible to know wether Diablo IV would even work on the ARM version of Windows at all.
If Blizzard were to release an Apple Silicon native version of Diablo, it would probably run perfectly fine with the M2 gpu, and have no performance hit over an intel Mac with eGPU. In fact it may probably run better if it's a native version for Apple silicon.
As is, and what is known, there probably won't be any eGPU support, and if there ever is a Mac native version of Diablo, it will likely out perform an Intel Mac with an eGPU.