@ Stupida
TPS is technically not a status, although it says Status at the end of Temporary Protection. Its just a humanitarian benefit. TPS beneficiaries should maintain their original status because upon the termination of TPS, the beneficiaries are reverted back to their original status, ie F1, F2, B2, J1, H1B and on. Therefore, its essential to maintain their original status along with TPS, if a person doesn't maintain his original status, upon the termination of TPS, that person will become status less which would be unlawful. Well, its not difficult to maintain other statuses while on TPS except B2, which would require travelling back and forth, which is likely not possible. So, I would say B2 case is a little complicated and needs an expert advice. I would recommend an immigration attorney. Because if his parents are denied reentry that would be a heck waste of time and money and a lot hassle.