I think this is why no one has claimed credit or responsibility for it, it just kinda popped up in loads of places at once and has just circulated. Whether or not they can maintain that anonymity is another thing.
Saying that there have been a lot of rumours and hints that Nintendo were planning to remaster SM64 and other 3D Mario platformers for Switch for the 35th anniversary so it's almost certain they'll chase it far if that's true.