Supers are medium and are competing in the medium senior division at CheerSport. They were asked (by CheerSport) to compete twice (once in medium, and once in large) in order to give Senior Elite some competition in the large division as they are the only team currently registered in Large Senior. Those are the facts on the issue.
Looking at it from a gym point of view it seems logical. If there were no other large teams the Medium/Large division would be combined. So it works out for everyone this way. Senior Elite gets competition in large, and the Medium teams are only competing against other medium teams.
I have no clue what the outcome would be should Supers receive a paid bid in Large Senior. My guess would be with worlds being a little more than only 2 months away at the time of CheerSport, and them competing in Medium the whole year already they would more than likely decline the bid and stay medium, but guess we won't know until February 19th.