Worse than just not supporting gaming, they're antagonistically blocking companies like Nvidia who tried to fill in the gap with external GPUs.
https://appleinsider.com/articles/19/01/18/apples-management...
If you want to game, you buy Windows, end of story.
I don't think any of those games are GPU intensive. Blizzard seems to want their games to run on as many machines as possible, and Rimworld and Factorio are both 2D.
They just announced PS4 and Xbox One gamepad support and had Mojang on stage to demo a new version of Minecraft in this very keynote.
Question is why people keep wanting MacOS to be a hardcore gaming platform.
I wouldn't recommend it for gaming as it doesn't shed heat fast enough. You can build a separate really good gaming PC for ~$1000 and still be far off from even the iMac Pro.
It's like the previous generation of Apple computers were primarily designed for people in crowded metros like Tokyo. I still don't understand Apple designers' obsession with compactness for their desktops at the cost of everything else.