Even if Alain did cheat his way through the final (intentional or not), the league is a done deal. You don't just give up a title because it is revealed the match was rigged in a way that is uncontrollable by the user who has the advantage. The only way your title is stripped off is if you do something illegal, and as far as I know outside influence that you have no control over is not illegal from your part. This like saying in a hockey game, you shoot the puck which goes in, but is later revealed some idiot from the stand was shooting a laser gun at the goalie, blinding him. So is the goal called back? No! What if the game was decided on that goal? Who cares, have to move on.
So no, Alain is not getting disqualified. Because if he was, you can easily do it the other way around and put the advantage on Ash's side, claim to the league staff later Ash had an advantage the whole time, and the staff has to disqualify him. Which is why outside influence is not considered when deciding what the just call is. Which is also why security guards are everywhere in sporting events; to make sure idiots are not rigging the match.