Depends on the move! For instance, there is a very good reason Machamp cannot learn Fissure anymore.

Probably if a Pokemon move is legally obtainable in Gen VI in any way, it should be fine. Previous tutor moves will need to be taught through Masters of Training or Guru's Wisdom, and Shifters can learn any move they need on their own. The TM list in this game is drawn from Gen VI, so former TM moves will need to be recovered through a Guru's Wisdom.

(As a note, nothing from Gen I or Gen II is legally transferable into Gen VI.)