Brother, first of all, congratulations on your H-1B success. That's a very interesting situation you just asked about. Since you are not going out of country for stamping (because you had filed H-1B as COS), I'm not sure if you don't take classes for Fall, what's gonna happen to your status until October 1. I think, to be safe, you should enroll, just for the heck of it. But, please consult an attorney.

Good luck, brother!! :)