I would guess that neither Valve or Epic will do that, it is up to game devs to do that. Mac is bad gaming platform, and dropping 32 bit x86 support from Mac OS didn't help
https://www.macgamerhq.com/opinion/32-bit-mac-games/
I think it is clear they dropped 32bit x86 support so it would be easier to develop Rosetta 2 (The x86 emulation layer). I don't really see why they would drop support otherwise.