This follows the Nintendo Direct's recent announcement of Switch Online having new games for it, but it would be in the form of retro gaming with Nintendo 64 and SEGA Genesis. Read Also: Nintendo Switch Online To Include Game Boy, Game Boy Color Games | Will This Incur Additional Payment? Game Boy for Switch Online Users would need to join the Switch Online subscription platform for this, especially as it is exclusive to the feature only. Nevertheless, the Switch would not magically have a cartridge slot for the GBA ROMs when it is available, and rather these games would be translated to the digital version and have it online.
This was with the Game Boy advanced titles and other cartridges that can fit the Nintendo DS or Dual Screen console, which still has the slot at the bottom. The arrival of the Game Boy for the Nintendo Switch has been long speculated, and it was known that Nintendo has previously observed the games to be cross-played between consoles. I'd imagine N64/Mega Drive are being rolled out first as they're more enticing things to prompt people to upgrade- Tom Phillips September 23, 2021 Fwiw, N64 and Mega Drive were the two NSO platforms I'd heard about alongside Game Boy/Color.