It's "breaking the rules" if you reveal a Tournament, ask the other person if they wish to reveal, wait for them to say "No", reshuffle to draw, and then the person reveals. It's too late for the reveal. Well really it's not a rule breaking; the reveal of the Province just doesn't do anything.
If you just preemptively start shuffling, then that's your fault, and you're technically not allowed to do that. So that is a rule breaking, but since your discard pile is not really ordered anyway, it doesn't matter much. You just put it back.