Somehow I doubt they'll ever do an arcade version for Soulcalibur VI, considering the state of arcades in Japan. So there is a possibility that they'll just develop the game on consoles (that, and players won't have to worry about Japan/Korea getting 2+ years of play before the rest of the world).
The last time an arcade version of SC was released was SCII, right? There was SCIII: Arcade Edition, but that came after SCIII came out. Since then, there hasn't been any arcade SCs, and if one for SCVI came out then it would come afterwards I'd imagine like DOA5. Which is good, I don't want to wait three whole years after it comes out for arcades just to play it at home.
Since an earlier arcade exclusive release would also at least cost them another year before bringing the game to console, I really hope they are clever enough to not do that now.
It's a shame to see 3D fighting games in this state this generation (while 2D fighters are flourishing). This generation might very well end in two years and there is still just Tekken 7, Virtua Fighter is as good as dead and SC and DOA don't get their act together. That all was actually foreseeable a couple of years ago already.