Staying more than 6 months is a direct violation of B2. TPS will make stay legal but won’t protect your former status. I’m trying to prove your point since your parents overstayed, there’s a high chance they’ll be denied at the POE. But I’m skeptical myself and don’t consider my assumption more credible. Consult an expert and please do let me know. daveraazshakya@gmail.com. Can I have your email address so I could contact you later because you and I have same situation.