A lot of past Nintendo consoles have made pretty major changes to the hardware and operating system compared to other console manufacturers, which makes backwards compatibility less likely. The Wii U basically booted into the Wii operating system to play those games. I imagine getting Wii U games running on the Switch wouldn’t be the easiest thing to do, though certainly not impossible. We don’t know a ton about what changes the Switch successor will make, so it wasn’t outside the realm of possibility that it would be the same.
surely they’d have to go out of their way to make it not be backwards compatible?
A lot of past Nintendo consoles have made pretty major changes to the hardware and operating system compared to other console manufacturers, which makes backwards compatibility less likely. The Wii U basically booted into the Wii operating system to play those games. I imagine getting Wii U games running on the Switch wouldn’t be the easiest thing to do, though certainly not impossible. We don’t know a ton about what changes the Switch successor will make, so it wasn’t outside the realm of possibility that it would be the same.