Fr. Hewko's answer?
Prescinding from commenting upon the dispute between l'Abbe Hewko and M. Johnson, Abbe Hewko makes an interesting argument at 11:19 and 38:20, where he says that no pope can create new rites for the Church (elsewhere implying that if he did so, these new rites would not be Catholic, and therefore Trent would not apply).
But if I understand Pope Pius XII correctly, he says precisely the opposite:
"58. It follows from this that the Sovereign Pontiff alone enjoys the right to recognize and establish any practice touching the worship of God,
to introduce and approve new rites, as also to modify those he judges to require modification."