Whilst I can't help you on the question of whether he joined the monastery, I can shed some light on his apparel. He appears to be of the traditional persuasion (he would celebrate the old Latin rite, the Tridentine Mass, rather than the
Novos Ordo, which is what is most commonly celebrated in the Roman Catholic Church today). The first photo you posted indicates this by the way the altar has been set up, the style of surplice on the altar server, and his preference for wearing a cassock. The second photo shows him also sporting a cappello, which complements the wearing of the cassock outdoors.
I hope you find out where he ended up