They already sell their games on Nintendo, Xbox, Playstation, GOG, Steam, etc. You can play them on a TV right now. Not to mention legit Neo hardware, PC emulation, etc.
A decent portable option is something we don't necessarily have. You can put an emulator on your phone and then use a bluetooth gamepad or shitty touchscreen controls, but that's about the best there is.
Problem with the mini is, it's not fucking portable. It won't fit in your pocket.
If the Neo Geo X were just the handheld, had decent emulation, and had a better screen it would be ideal. It would provide something that isn't done much, much better elsewhere.
But the Mini? What exactly does it do again? Why would you hook that to your TV instead of just buying the games on your digital game platform of choice or emulate them for free?