I personally consider GT an alternate timeline, it makes things simpler lol
Don't worry, Akira does as well.
I don't know where fans get this non canon stuff from, Akira himself calls it a alternate universe and says it did happen, the guy oversaw the production of GT (even though he had nothing to do with the story) so if he did not want it to happen he could have easily put a pin in it.
I just think fans that don't like GT just constantly pick on it, hence the "non canon" thing many fans started bringing to their arguments which was then followed by a "it never happened" even though the creator of the series does not agree with them.