Yeah, just a handful of games with issue, which they are investigating and may end up working.
Happy about JoyCon and ProController working with Switch 2. I don't think my wallet will allow me to buy Pro Controller 2 (or whatever it's being called) right away, so that help with.
Well Nintendo actually has real people which test (for minimum wage) every update to every game before they can be released. So I assume they did these tests, too.
There is a reason that most games are listed as "capable of starting, more testing required". It should not be too hard to set up automation that loads a game on to the Switch 2, launches it, and checks that it did not crash within 30 seconds.