when they do decide to implement chocobos I personally think it would be awsome if Chocobos could be more like retainers. For example: You do a quest and get access to a chocobo whether you are just able to rent one or its yours forever like a retainer and then when you exit the city you can summon it.
As for the dressing part If you had ownership over the Chocobo then you could purchase or craft armor or attire for it. Some things could give it stats to run faster or leap over certain terrain.
Just giving my thoughts on it.
thanks