We would have had him on a reserve list of some sort (i.e. a did not report list). As such, we could have brought him back without him going through waivers. This assumes we did not relinquish his rights (which I don't recall hearing we did).
Yeah, my understanding is that as long as he would be signing for the team that already held his rights that he wouldn't have to go through waivers.
I hope we still held on to his rights. He might not be ready now, but the potential is still there, he's young and who knows what the future may hold. If he does mature and become that player that many thought he could be it would be nice to still have his rights if nothing else.