>>9009577When GT came out I considered it canon simply because it was after Z and didn't contradict previous material (at least in a large way)
The only real reason I think GT is non canon unlike super is that Super retcons a lot of shit from GT and both existing in a linear fashion after Z wouldn't make sense. If that scenario did occur (God forbid) maybe I'd consider the next arcs after that non-canon but I'm not sure if I'd care enough to make that distinction begin with.