I don't see this happening. Imagine people storming the Ul'dah Adventurers' Guild on Chocos >_> or going up the stairs once the airship ports get open and what not. Just unnecessary clutter, imo. Then there's lag issues, Chocobo butts in my face at market ward entrance etc. It just reads chaos to me. And people can't be that lazy to walk in the cities.... can they? o_O???

The Chocobo stables inside the cities might as well serve for personal mounts once we get them, to access the stables via them, check Choco progress etc. or if those are ment for rental perhaps you'll just appear outside city limits once you rent one. Or they'll move those NPCs (stables) somewhere closer to city entrances, or give us new NPCs.... Just don't see mounts functioning well within city limits.