“... the nature of Purgatory is an admitted area of unsettled knowledge in the Catholic Church ..”
The Greek Orthodox church doesn’t have that doctrine (neither do protestants); so it’s indeed something that is ‘unsettled’ and may be dropped one day by the Roman Catholic Church.
Yep...just like "limbo "
The Orthodox don’t call it “purgatory” (that’s a Latin word), they call it “spiritual toll-houses”.