They didn't demo gaming to suggest this is a great machine for gaming, they demoed it to show that it was possible at all. The previous version of Rosetta during the PowerPC->Intel transition was not known for performance.
If gaming is important to you and you want a Mac then you want an Intel Mac or whatever games are released for Mac ARM. Emulated games are not going to compete with native.
It doesn't really matter what the graphics performance is, on high end macs they'll still ship a dedicated GPU from AMD. What matters is that the game is GPU-limited instead of CPU-limited.
Having gone and checked, no. Not even close.
(Nor would it be plausible to expect to. But it's clear Apple have made a choice here, and that is that if you're a user who wants legacy software or desktop gaming, Apple do not care about you compared to their margins. It's that simple.)