I would not be surprised that an NDA would be required to attend the taping of a show like Shark Tank. The contents of the show could be considered privileged information and would therefore require this sort of agreement.

That being said, I am not sure why he would make a point of stating that he was going to be attending the taping at all if it were no more than audience participation. It seems like more is there than what he is able to say at this point, so just being a member of the audience doesn't seem to hold water.