Sony has ported/remastered a bunch of PS4 games to PS5 despite the latter being fully backwards compatible with the latter. It's easy money and provides some decent schedule-filler, so I'd expect Nintendo to adopt a similar approach.
IMO Nintendo will choose to port or not port Switch games to Switch 2 based on whether the IP is getting a new entry in the immediate future. The expectation is that the next Mario Kart and 3D Mario are going to be launch year titles for Switch 2 so I dont see Mario Kart 8 Deluxe or Super Mario Odyssey getting ported to Switch 2. OTOH the next 3D Zelda is probably 4-5 years away so enhanced ports of BOTW/TOTK makes sense.
Its not a 1:1 comparison because Sony devalued a lot of their games on PS4 through sales and most of the games released in the first 3 years where cross-gen anyways.
Sony had big incentive to re-release something like TLOU or TLOU PT 2 Remasters where they can sell it again for full price (and on PC), compared to the 10 bucks the PS4 copies where being sold at for years.
Zelda is still selling and its still full price - will the biggest Switch games get some updates/patches on Switch 2 ? Very likely, but i dont think Nintendo necessarily is gonna want to re-release all these games though when, the practical difference would be so low.
BotW and TotK are still 70€ on Switch, and they aren't aren't gonna stop selling them anytime soon. So all they need to offer would be updates/patches for the games when run on Switch 2.
Business wise i don't see the benefit of Sony like ports for games that already have sold millions on Switch and could just get updates.
BotW is a special release so they might make an exception for this one but i think for the most part they are gonna push for new releases, while old Switch released might get an updated cover promising enhanced features on Switch 2.
It's not the same but going from GBA to DS or even DS to 3DS, they really never bothered with released of games of games the previous gen, that were supported through BC.
We will have to see how BC is exactly handled, but I don't think Nintendo is gonna go full into Remasters of Switch games having too big of a retail presence for the new system - when their messaging is clear about OG Switch games running on the successor.