Last I checked "eluded all but a few" in regards to an entire race means exceptionally rare and we still have yet to see a single Garlean even among the special NPCs who can natively wield magic. The Encyclopedia also isn't exactly an all knowing source since it's written in-universe and has been wrong before. Still though, that's a whole lotta reach to make a race that's not even that aesthetically different from what we already have just to play something that's even edgier than male au ra.
False claim how? They've already been up and down on the technical limitations and that the time and labor costs increase with every additional race/gender added. While they said we're getting male viera in 6.0 and female hrothgar "later", they also said that the work to make male viera was done on the graphics team's free time. Us getting male viera isn't going to magically allow us to get everything under the moon. They didn't open the floodgates to new races as much as they somehow actually managed to squeeze a few drops of blood from a stone.
Right now as the game exists, it's going to be extremely difficult to add anything new for races. To think otherwise for the game's current state is being delusional. Yeah, they have talked about an overhaul, but the amount of work required for that would delay an expansion at best and we have no real leads at all on guessing when or if that may actually happen. EW will be the end of the current story and the beginning of a new one, separate from the rest. Does that mean that 7.0 will be the overhaul for new players incoming? Maybe, but we haven't even heard whispers about that and EW isn't even out yet so there's nothing we can do except fruitlessly argue on the OF and I've been in this game for over a decade now and learned a long time ago that there's no point in wasting mental energy on maybes and hoping to get everything you want.
Even if all of the above happened and we got our overhaul and they were going to add a new race, do you think Garlean would even be on their list? I personally don't think so, looking at au ra and how they preferred hrothgar over viera, which was tacked on for the fanservice. Garleans don't give us anything new at and are just hyur-eared elezen with a white ball stuck in their head.