Not surprising, but interesting...
Given that the concept of "Divine Law" is a revelation (protestant term) as defined by Catholics, revelation should be based on and inspired by Holy Scripture...
As far as I can tell the sole requirement to be leader in a body of christian believers is to be a Christian first...not a Roman Catholic... (Not completely sure Pope Frankie can pass that test) ..
There is nothing in Scripture that makes non Catholic believers apostate, heretics and schismatics...
That's strictly is man's tradition... not revelation, thus not Divine Law...
I’m not willing to get into a Protestant vs Catholic “debate”. If someone else wishes to get into it with you, they can. I don’t.