Leaked Game Boy emulators for Switch were made by Nintendo, experts suggest | Ars Technica
Upgrade 5.1inch Hand held Gaming Player 8GB ROM PSP Console Hand Game Machine Built in 3000+ Games PK Nintendo Switch|Jewelry Tools & Equipments| - AliExpress
NES Famicom Complete Roms Collection for Nintendo Switch NSP | nsw2u.xyz
It's apparently easy to load your own Roms into the Switch official NES app - Wololo.net
The Nintendo switch gets stock android via a custom rom