Well yes, yes they did. It is called Canoe and is for example running inside the SNES Classic Mini.
And that is not the only emulator they wrote.
Writing an emulator is not some obscure magic, and it is way easier if you own all the schematics and other Information used to build the original hardware.
You think they wrote their own emulator instead of just taking one of the free ones on the internet (who they will likely sue later). That’s cute.
Well yes, yes they did. It is called Canoe and is for example running inside the SNES Classic Mini. And that is not the only emulator they wrote. Writing an emulator is not some obscure magic, and it is way easier if you own all the schematics and other Information used to build the original hardware.