I'm just giving you a head's up but they might go over your application during the interview, just to make sure everything is complete; at which point they'll ask you about your summer class... So be prepared to tell them why... but don't lie because they can tell.
I don't think you have to take all the classes you listed on AADSAS. Things happen and they know students don't end up having the same schedule they listed on AADSAS, especially since you're signing up for classes months before the semester starts and you have the whole summer to make changes! Plus, AADSAS gives you the option of updating your courses in November.