I don't think anyone has mentioned this yet.
Giovanni and Janine weren't Gym Leaders at the same point in time. Any thoughts on this? I doubt they would invite a known criminal organization leader in to a tournament of respectable trainers unless he was still a Gym Leader and it was still a secret, unless it's not supposed to be considered canon and these are all cameo-like appearances.
And Blue, would he be there under his most recent title of Gym Leader or his highest title as Champion?