Board Thread:Pokemon Arena X- CAMP/@comment-4148296-20140322192003/@comment-5537612-20140322220334

PachirisuPlusEmolga wrote: It learns them, try it on showdown smart one. Don't sass.

Checked Serebii, it indeed does learn them as egg moves. Bulbapedia seems to be lagging behind.

Though I have to say, Mightyena would need a lot of breeding in order to make the mega evolution worth it, which in my opinion is more effort than I'd consider desirable.