If you somehow think that Mysteryman isnt Gaster (despite the evidence) then please explain why Toby hasnt developed mysterymans Mystery! If he isnt Gaster then every code/Funevent/riverperson mystery from Undertale is in Deltarune EXCEPT Mysteryman. Why would Toby leave him out?
No they’re technically not wrong. Not once has mystery man ever been referred to as gaster. Every time fangamer tried to make merch of gaster using mystery man they get it removed by toby