Did the SSPX's seminary instructors drastically change within the past few years (since the opening of their seminary in Virginia?)?
Not sure, except that I know none of the ones who were there when I was there are still there. Fr. Peek was the last.
But that's less a problem than the program for formation.
Fr. Rutledge once announced (search CI for "Militant Anti-Resistance Sermon in St. Paul, MN"), in attempting to refute the Resistance in 2013, that the seminary still has all the same books as when he was there.
Well, he was ordained in 2009, and was in the first class of all-LeRoux priests.
But if the books and classes were the same, the spirit was completely different:
No more anti-modernist spiritual conference 3 days/week; that was the first casualty, which went out the door with +Williamson.
The new formation was all about virtue, not combat.
Meanwhile, the old hats sense the change, and go along or leave, so what is left is comprehensive metamorphosis into something very close to the FSSP.
Identical, really, except for the certain validity of orders.