It's worth pointing out that there is precendent to SE taking a previously-1.0 exclusive item and making it available to everyone in 2/3.0:

http://na.finalfantasyxiv.com/lodest...m/65b9ed2a045/

The Star-spangled subligar was originally a quest reward for finishing the last available Fisher quest at level 36 in 1.23. When 2.0 launched with the completely new Guild quests that ran all the way to 50, they completely did away with the old quest system and the item because unavailable to anyone who hadn't completed the old quest...that is until they added it as a reward for finishing the Postmoogle quest chain a few months ago.

In this way the item reward was very similar to the level 30 Wandering Minstrel quest that became unavailable to anyone who hadn't completed it by 2.0 launch. So there IS a possibility that SE will re-introduce the old Goobbue mount item as a reward for some future quest chain.

If I'm being honest, when they re-added the subligar I was initially upset that my item was no longer "special" to me and a select few, but over time I'm glad that more people have had the opportunity to share in what is a pretty unique and cool-looking item. In this way if they ever added a way to obtain the mount, I would probably be a little sad at first, but also happy that a greater amount of people can enjoy a cool-looking mount.

That said, as far as the Legacy chocobo/mark are concerned, SE did explicitly say those would be unique rewards to players with "Legacy" status, and I think it'd be better if they stuck to their word on that. Any other 1.0 item, though (looking at you, Onion set!) I can understand why they'd bring back.