I could just be dumb, but I hope that it'll still use the switch cartridge. Like how they did it with the DS line up until the 3DS when they changed it. I could see them potentially doing that too. If it does I'll finally jailbreak my OG switch with the tegra exploit. Just been too much of a scaredy cat to do it.
I was thinking this earlier today. If they do make the switch 2 compatible with current switch games, physical and digital, it'll be a damn near instant day 1 buy for me.