Sorry to burst your bubble, but never would be the right term. BHVR doesn't have the money or the devs to introduce new factions, be it T'au or any other one. Heck, even if you give them 500k or more there are more important things to do for EC than another faction.
you can only say that if i said when tau release date this year ? , please read my post again and comment , i am really tired of people comments just after they read the title
Oh I did, You asked when, I said never, because of reasons. Point stands. I wont comment the 2nd part, because I'm tired too...
So here's a thing I posted: Now with that out of the way, I still have no faith in the capability of the studio to produce anything of the sort. I actually think Dark Millenium is farther along in this direction because they bothered to model Guardsmen, at least for pics. The entire point of this is, sure Tau can be done, you might even get away with the B.S. single character model if you do nothing but Fire Warrior (Tactical), Pathfinder (Long range/support), Fire Warrior Breacher (Close Assualt), and a even a fucking Ethereal for healing/support. Before anyone says "lore," there is no lore in this game and all of the current classes and their appearances are made from bastardizations of GW rules. There's not even a concept of healing in anything else. Apoths are primarily corpse looters, and the psykers have better things to do than save the pleb. You could even do a comically bad 'nothing but shrunk battlesuits' approach and just throw all of those in. But there is no capability, nor the will, to do so. The devs can only bother to model a bit once every 6 months, so we end up with recycled kommandos and possessed (and eventually a woeful autarch) compared with the Legionnaire, which while having some work done, is still mostly recycled. The newest thing is the skull helmet and that thing looks demented. And so while I would love the Tau, I'm essentially at the point where they shouldn't bother. They'll be left buggy, unbalanced (not even in their favor), visually stale, devoid of players as everyone goes back to LSM after trying to melee, and just another sad reminder of what could have been, just like Eldar, Orks, and to a lesser but still significant degree, CSM and SM.
The only faction i can think of being a slight posibility of ever apearing would be a goth/emo/bdsm version of eldar, reskined purple and black saying "AHOY ME MATE READY THOSE BOOTY KNIFES"