PrimaGaga

It seems to me like much more than a cameo. Majora's mask being on the wall in this timeline could be not unlike the presence of those twin rova witches in majora's mask being just two witches and not trying to revive ganon or whatever their deal was. By which I mean, in one timeline they became pretty important, but in another they're just there.

Which I think is much more interesting than just a cameo

there is also supposedly part of the Hyrule map from Skyward Sword hidden in his shop. It's probably just a Cameo. Like when the Happy Mask Sales Man (MM) had a mask of Mario. And you could see paintings of Super Mario characters in Hyrule Castle (OoT). So yeah, I'm gonna say these are all cameos.