Anything to get a jump start on filling the class. I would suspect you would have to pay a significant deposit to commit to the class, but otherwise I can't imagine it could be legally enforceable. They do not have to adhere to the AADSAS traffic rules either so they theoretically can offer spots and ask you to accept on the spot. (Oh those days before the traffic rules during the dark times of dental admissions.)
Sure, NYU ultimately gets you with $5K over several stages to commit to your seat so expect similar language for a sizeable nonrefundable deposit.
Please report what the real conditions are here and on the Workman HPU thread.