The Church's (pope's) determination of sainthood is an exercise of Its infallible teaching authority.
No, that would be the catechism, an exercise of the ordinary Magisterium. But while there is no demand we honor St. Bernadette, for example, any Catholic worth the name does. And the tests were provided by The Church. And yes, just in that way, once a Saint, always a Saint.
But see - you want to have it both ways. Because when your regime came in, they said, oops, here's a couple we found that don't belong, namely St. Christopher and St. Philomena. It's said that Sophia Loren, in one of her better years, rode around the collonade at St. Peter's with a statue of St. Chris, just to make a point.
So, either it's one way, or it's the other. I'm saying, that in future, all of your new 'saints' are going to have to be thrown out, en masse, and each individually reconsidered according to the established, holy and traditional norms - period. There is no other way. And by that holy standard, many may indeed turn out to have been Saints, as proclaimed by The Roman Catholic Church. We, as Catholics, DO want to believe that when The Church says a Saint is Saintly, that they really are. You can't categorically say that about the sum of those promoted under the J-Pauline regime.