Considering it would be the first Halo movie, and that since it has Halo, the majority of the public is going to be thinking 'Master Chief', I don't think that'd be a very smart decision.
It was supposed to be rare, the IWHBYD skull was ludicrously hard to get until someone hacked the game and found out how. Then it was spread to the world. It was supposed to be a fabled armor like recon.