Welcome back:
When you say greyshirted I take that to mean you are now enrolled and are taking less than 12 units. Is this correct?
If you have not signed an NLI then, as far as I know, you are not contracted to the school, athletically at least.
I would call Rick at Informed athlete and ask him. He may pop in here and see this but like I posted before make sure you are getting informed answers.
http://informedathlete.com/tag/rick-allen