I don't actually see why this wasn't done, I'm sure FFG has considered it. With all the movie releases that are sure to come, not to mention those already out there, card packs for new characters should be a thing, right? Sorry even if this suggestion has been made. The point is, however, that we all likely have enough T-65 X-wings to satisfy our play. Or TIE fighters. Or TIE/FO's, etc. etc. But I don't think most people want to have to buy an entirely new ship for, say, a Blue Leader card from Rogue One if FFG made him. Or an unreleased pilot from The Force Awakens, etc.
My vote added for card packs for new pilots, beyond what is out there, if the rules for these new pilots can be made fun. I'd rather see this than some esoteric reach for a new character through a TV series. I'd much rather see this than throwing new characters into some ship release I don't have an interest in (or that would be price prohibitive, like a big ship). Don't get me wrong; go ahead and release more C-ROC expansions. But it's still better, imo, to have card packs as a separate product for new pilots and abilities, especially if they are flying things that FFG has already released, like T-70 X-Wings or whatever.