TM - YesIf a Pokemon acquires a non-level-up move through a normal means like Mirror Herb/Breeding/TM, can they relearn it if you swap it off, or do you have to use said method again?
Mostly curious for rotating certain coverage or utility moves on my raid mons vs raising secondary copies to fill other niches
Bred an egg Move - To my recollection, yes
Mirror Herb - No, but it's at least easy & quick enough to do again.