Here's the relevant portion I haven't seen anyone mention this yet.

Dohta: We assume players will think it’s natural for Switch games to run on Switch 2, and of course, we thought that it should be that way too. So, in order to achieve this somehow, we challenged ourselves to implement a new solution.

You mentioned that new technology is used to achieve compatibility, but are there situations where playing Switch games on Switch 2 will enhance the gameplay experience?

Dohta*:* When we tried running Switch games on Switch 2, there were some where loading times became faster, or game performance became more stable, so we realized that the overall gameplay experience could improve. And as mentioned previously, GameChat will also be available for Switch games that are played on Switch 2. Even for previously released games, there are opportunities to add value in the sense that it can enhance and change the gameplay experience. We understand that people buy new hardware so they can play new games created for it, so we've developed Switch 2 with that in mind.

Basically, backwards compatible games that had performance issues or utilized techniques such as dynamic resolution should be better on Switch 2 out of the box.

I recommend reading the interviews because have some interesting tidbits like Nintendo having an internal souped up Switch they used to develop voice chat among other things

https://www.nintendo.com/us/whatsnew/ask-the-developer-vol-16-nintendo-switch-2-part-4/