An official Game Boy Advance Emulator could be coming to Nintendo Switch

gamesradar.com:

There’s currently a rumor circulating that Nintendo Switch Online could be getting some Game Boy games added to it soon.

This rumor began with Twitter user @trashbandatcoot (via Nintendo Life) who claimed that "Nintendo's official Game Boy Advance emulator for the Nintendo Switch just leaked." According to this user, a list of files shared online included a GBA emulator - developed by Nintendo - that at the moment is codenamed "Sloop" as well as a Game Boy emulator called "Hiyoko." 

So Nintendo's official Game Boy Advance emulator for the Nintendo Switch just leaked. Now it's just a matter of waiting for NSO to add GBA. pic.twitter.com/mEJcKrRtzLApril 18, 2022

It looks like the two emulators were developed by Nintendo of Europe’s NERD (Nintendo European Research & Development) team in Paris, which previously worked on Super Mario All-Stars. Not only has it been brought to light that these emulators could exist, but it also looks like a list of potential titles coming to the rumored service has also been found.

According to another Twitter user @Mondo_Mega - who quote retweeted the original tweet above - a number of GBA games for the rumored service have been tested including Fire Emblem the Sacred Stones, Kingdom Hearts: Chain of Memories, Kirby and the Amazing Mirror, Mario Kart: Super Circuit, Pokemon Pinball, and many more. As for the Game Boy Color though, @Mondo_Mega has also shared that they’ve only discovered a few titles so far including Super Mario Land, Link’s Awakening DX, Tetris, and Qix. 

It’s important to note though that, as pointed out in the tweet, "Tested is the key word" here, meaning not every single game tested during the supposed development of the emulators will definitely end up on the service,