Hmmm. The more I stewed on this the more it's kind of what I wanted, albeit as always the Apple-ized version of it.
I've been saying since it launched that they were sitting on a heckin powerful microconsole with the ATV, and now that they dropped the wand controller requirement it could make for a nifty microconsole. But the software wasn't there, so I wished for them to fund some exclusive games.
With Arcade, they are funding exclusives, and those games are said to work (or be able to be made to work) across macOS, iOS, and TVOS. So if any of the exclusives are good, I did kind of get the push from them for ATV games, and it running on macOS come to think of it is an unexpected bonus.