Help a Crusader Kings 3 player with some "lore-accurate" roleplaying

One of the many options available to a Crusader Kings player is to restore the Kingdom of Israel as a jewish character. I’ve done this as a rabbinic bavli king of Babylon, and had a question about how a king in his position would go about his next steps, particularly in reference to aspects of the faith. Jerusalem is his capital, and he has built the Third Temple. Where I’m hitting a roadblock in terms of my understanding of things is the Prophecy of Malachi; a high priest cannot be appointed until either the coming of the Prophet or a suitable candidate being found amongst the descendants of Aaron. Given the circumstances of restoring the Kingdom of Israel, Jerusalem being retaken, and the building of a new temple, would such a medieval king be considered worthy of appointing a new high priest? There is a decision in-game related to this, but I’d like to get the opnions of some jewish people on the matter.