The way backwards compatibility has been integrated with Switch 2 already made it clear that eventually all Nintendo consoles will become a part of NSO. Admittedly, this "all" didn't include the Virtual Boy because of how obscure it was.
The Switch 2 eShop combines Switch 2 and Switch 1 software offerings into one big store, so gone are the days of shops getting closed down eventually, like it happened for the DS, Wii, 3DS and Wii U in the past. As for more old platforms getting added to NSO, it's reasonable to expect progress in chronological order, so the DS would be next, followed by the Wii. These two I can see being added during this generation, something like DS in 2028 and Wii in 2031 because Nintendo is opting for a slow, but steady release schedules of classic games.
Legend11 correctly predicted that GTA IV will outsell Super Smash Bros. Brawl. I was wrong.
