But it's not April fools. The software format that Nintendo uses (NSP)s of each emulator have leaked. And for the Gameboy games, each one is a separate NSP which is kind of a lot of work to do just to fake Gameboy emulation. The software itself points back to NERD as well. The emulator functions, rewind, dev tools, etc. are also in these NSPs. This could be a very elaborate hoax and is still a rumor at this point, but it would have been done on April fools, not today.
If you need any more convincing, video of the emulators in action were taken down shortly after being posted. And not by the poster's own will.
I still find this too good to be true.