Maybe if they are back doing non-Microsoft build work, they can soon support Mac with case-sensitive filesystems?
Seems somewhat unlikely to me. Now that OpenGL is gone from MacOS, the Mac is basically dead as a cross-platform gaming system. Who's going to rewrite their renderer on Metal just to target such a tiny platform? Maybe if UE or Unity do the work, games might still get Mac releases...
There are libraries like [1] that expose a Vulkan api/abi on a Metal backend.
Valve uses MoltenVK[1] on their own games. They have used it since 2018 for Dota 2[2], but I can't find a lot of uptake by others.
[1] https://github.com/KhronosGroup/MoltenVK [2] https://www.khronos.org/news/permalink/vulkan-support-for-do...