I wouldn't be surprised if they went the Worgen route and added some sort of "token mount", like a recolor of some other Dragon Isles mount, to serve that purpose. Worgen were released with the Running Wild racial and no racial mount, with Blizzard adding the Mountain Horse and Swift Mountain Horse mounts to a Gilneas vendor 3 patches after release to throw a bone to us mount collectors. The same might not apply here since Dracthyr can be both Alliance and Horde - unlike with Worgen, their addition doesn't create an imbalance of mounts available to Alliance collectors vs. Horde collectors; both sides would just not get any new mount.
That being said, even as a mount collector, I'd be willing to forego the addition of a new racial mount if it means we get full flying with the Dracthyr's wings.