Personally though, I'd like to see something new. I don't see any real reason to bring Maz back and if he did come back I'd want him to be different than last time if we were to fight him, or say something that enhances the lore.
They should have one of the mummified Yiga from before the calamity instead. I doubt Kohga was the leader back then as he doesn't seem ancient and shrivelled like Impa.
Maz has fulfilled his purpose and had a good sendoff finally being able to pass on.
I think it'd be awesome if he did; the Sheikah monks could easily be fit into the narrative with the focus on what happened to mummified Ganon.
Their bodies faded away but they could come back as spirits like the Champions. If Nintendo wants them there they'll make something up.
Maz Koshia looks basically like the other monks but something about him stands out to me. Probably the epic boss fight and how he guided you in Champions' Ballad. It'd be great if BOTW2 added to his backstory.