Since the topic is specifically about trios it is obvious though that people went on to say nope about them having their own game as that's actually true in this context.
Tidus and Wakka are from FF X while Selphie is from FF VIII, two different games taking place in totally different worlds. They do not know each other nor do they actually form a trio in their "original" games.
Not to even talk about these characters in the KH series being completely different incarnations to the actual FF characters in the first place.