He's just as canon as his RSE Counterpart thanks to multiverses.
Only reason they didn't use him is for nostalgia and the fact that Zinnia prevents there from EVER being a scenario where ORAS Archie or Maxie can truly succeed, as even if they do, the Meteor will just fuck up everyone because Zinnia won't let them teleport it away.
And without the Protagonist, Fug won't bother destroying the Meteor because Zinnia's too much of a cheeky cunt to be chosen, and no one else is worthy.
