The question is whether the person in question is a saint to begin with. After Vatican 2, the standard for canonization was lowered to almost nothing. That makes modern canonizations very questionable
It is not the procedure which make the canonizations infallible; but once again, it is
the pope’s approval of the universal Church’s veneration of a saint, whether formal or informal, that is protected from error by the Holy Ghost.
Therefore, if "pope Francis" is indeed pope, then we have no choice
but believing that John XXIII and John Paul II are indeed reigning in Heaven with Christ. We are not obliged to pray to them specifically; but at the very least, we must believe that they do "reign with Christ" in Heaven. Same with Mother Theresa Calcutta, the native St. Kateri Tekakwitha, St. Martin de Porres, or the other hundreds and hundreds of new-saints canonized by the communist, miserabilist church, in recent decades.
JPII alone canonized more than 400 people.