Mostly posting because there has been zero official word from anyone in the Activision / TH camp.
If you buy the game on Switch digitally, you will get an entitlement to download a copy on Switch 2 at no extra cost. This is the Switch 2 version and not just the Switch 1 version downloaded on Switch 2. They are two separate versions.
If you buy the Switch 2 version, you do not get the Switch 1 version, it only works forward, not backward.
This was believed to only be available on the Deluxe Edition of the game, but has since been shown to work on the standard as well. Unless you really want Doomguy, I'd say save the 30 bucks and go standard. I might have to email them about getting my extra 30 back lol.
I do believe this is ten words.
Edit: aha! I got them to refund me in the end. They were actually really cool and had it done within half an hour of my email.
Bro what the heck, is that the Doom Slayer?