If the trend with recent events continues, the only way this is going to be addressed is if they add something related to the problem onto the mogstation store.

They didn't allow multipiece items to glamour over single piece items until they started selling the multipiece only "Antecedent's Attire".
They didn't add the special animation functions to the gilded magitek mount until they were selling new magitek mounts in the store.

I doubt we'll see a change to this unless they sell a similar outfit on the mogstation store. Maybe we'll get a special easter themed chocobo suit in the future, and a year later when they add it to the mogstation store, they'll update both items so the tail is properly hidden.

There simply is no precedent to them adjusting existing outfits if it won't make them a buck off of the mogstation store.