Well, a lot of them are. I keep having traditionalist Catholics tell me that I MUST follow the magisterium in all things. Trid has said that to reject even one thing the magisterium says is the same as rejecting everything. These same traditionalists tend to say that the magisterium has never, ever changed a teaching, a belief that can only be supported by denying historical fact. 

I believe thats the sort of thing justmaybe means.