Most likely, the new rule is being put in place, so they no longer need to accept underqualified (but well connected) new recruits to the teachers circle.
Either that, or its going to be used as a way to ax the dead weight they already but don’t have the guts to fire on their own.
Regardless, don’t sweat it. If you have the desire to get a degree, it can only help you. If you don’t want to / can’t get one (and the school really pulls the trigger), if you’re good at / enjoy what you do, there will always be a place for you in education. Somewhere, someplace and at a rate that might (pleasantly) surprise you