No, I do not believe those physics professors would publish any "junk". I expect some research reaches a dead end. However, those professors seemed much too driven by the pursuit of knowledge to waste their time on useless research.

Though the math is beyond me, theoretical physics is pretty much all math. The math being developed may or may not be useful eventually, but it adds to the knowledge base. I think "is this testable?" is the wrong wrong question to ask.