New Races.

[White_Wolf_X]

Pretty sure Yoshida said that they won't be adding anymore races, because of the amount of work it take to make every ingame item fit onto a new body type.

Also let's maybe get female Hrothgar and male viera before even thinking about more races.

[Kemiko]

Pretty sure Yoshida said that they won't be adding anymore races, because of the amount of work it take to make every ingame item fit onto a new body type.

This right here. When Hrothgar (Ronso) and Viera (Viis) were added for 5.0, it was explained that this was going to be the last time they implemented a new race to the game. If I'm not mistaken, it was Hrothgar, specifically, that Yoshida wanted to add despite the fans desire for Viera (dating back to the pre-ARR race addition vote) and, due to the resurgence in popularity for Viera thanks to the Ivalice Raids (and showing how they'd look via Fran) Viera was added at the same time.

Edit: To answer the hypothetical nature of the topic, I don't think such a thing will occur for the aforementioned reason although I would love for them to go back on that declaration and add more. There's plenty of available races in the franchise that'd I'd like to see (the mentioned Gria would be fantastic imho, or the ratfolk as seen in FFIX though I wonder if the design team would believe it'd clash with the Qiqirin) so, I wouldn't be quite as excited if they announced another new race unique to FFXIV.