Poochy ain't stupid. ALLEGEDLY.
http://www.nintendoworldreport.com/news/63729/first-three-super-mario-advance-games-to-join-expansion-pack-gba-library-on-may-26
Just in time for the digital release of the Super Mario Bros movie, a trio of remixed Mario titles are hitting a Nintendo Switch Online Expansion Pack library.
The first three Super Mario Advance games - GBA remakes of Super Mario Bros. 2, World, and Yoshi's Island - will be available in the Game Boy Advance library following an update on May 26. The remixes add new voices and features to the classic Mario adventures.
Super Mario Advance 4: Super Mario Bros. 3 was one of the inaugural games for the GBA library.