Well, that's traditio.com's opinion. I've never seen any serious theologian claim that mandatory celibacy is part of divine positive law. If it were, there would be no "mitigations" possible.
Probably not, but my point in posting the clip is that "serious theologians" (e.g., St. Jerome) have maintained that celibacy is of Apostolic origin.
Others, admittedly, have disputed this. But without a definitive pronouncement from a Council or the Holy See it is impossible to maintain -- as most participants in the debate nowadays do -- that the issue is merely one of discipline.