I would LOVE that. Of course they should do that. Man’ari are not Draenei–they are fel-cursed mutations.
It’s no different from choosing to play as a Dracthyr.
Players can choose to DPS or Heal, and some of them also wish to fly. That’s no different from choosing an Eredari that has wings who can fly.
Once you remove your wings at the barbershop, poof, the flying ability is no longer usable.