Pokemon Trading Has Been Tested On Nintendo Switch Online's Game Boy Emulator

Pokemon Gen 1 to 3 games haven
Pokemon Gen 1 to 3 games haven't officially made it onto NSO yet, but a programmer demonstrated that trading should work flawlessly.

12 Game Boy Advance games that would be must-plays on Nintendo Switch

Nintendo Switch Online New GBA Leak - Checkmate Gaming.

Nintendo GBA Emulator For Switch Online Has Leaked - Report - GameSpot

Nintendo Switch Online - Every NES, SNES, N64, Sega Genesis, Game Boy, And GBA Game Available

Alleged Leaks Reveal Game Boy And Game Boy Advance Games Coming To Nintendo Switch Online - Bounding Into Comics

Looks Like Pokémon Trading Already Works On Switch Online's GB & GBA Emulator : r/nintendo

Nintendo is adding Game Boy and Game Boy Advance games to Switch Online today

Is Nintendo Switch Online on the verge of receiving GBA titles? Recent reports would suggest so

LuigiBlood's Blog — What's the deal with the GB/GBA Emulator Leak?

LuigiBlood's Blog — What's the deal with the GB/GBA Emulator Leak?

Can you play older Pokemon games on the Nintendo Switch?