I Still need to watch the video but forbidding the seminarians from speaking to the faithful makes sense. They know too much!
This is a huge red flag.
As you know, I was a seminarian in Winona for over 3 years. There was no such prohibition at the SSPX seminary. We were human beings. We could make phone calls home (we had to share the (2) phone lines with our fellow seminarians though...there was a 15 minute limit per day I think). This was before cell phones.
And we certainly could talk with whoever we wanted to during vacations.
Now there IS a general rule of silence, and on Sunday morning there weren't any recreation periods. So that would be the only thing stopping us from talking to them. But they could have taken any of us aside and asked us a question, and then we could have (and would have) responded -- maybe they could give us their phone number, and we could call them that afternoon or evening during recreation.
Just knowing the situation there, this prohibition on speaking to the laity looks really bad.