I would strongly advise against that. Reason: KOEI TECMO did a pretty poor job of porting Dead or Alive. They didn't even support controllers correctly and still haven't fixed various issues causing crashing. Maybe they will do better with Nioh but I would wait to find out before paying them a dime.
P.S. Wouldn't this be a JRPG?
I think it will probably be alright? I haven't played a really bad port in a long time.
Porting games isn't as hard as it used to be. Consoles used to have very different hardware to PCs but now they have, what, a few 1.6ghz AMD cpus? It's just x86 cpu architecture like PC. Probably about as powerful as a gtx780 machine.
I think a PC version must have been considered for a long while. It's due out in a month so there's no way they just started it. I'd say just finished it and are going to polish it for a month.
Dark Souls, the online petition, the terrible port, the community mod to fix it, the massive PC sales,etc. Team Ninja watched all of this happening. From the shadows, probably. I don't think this is a rushed cash grab. It's all been planned based off the path of Dark Souls!
Not supporting controllers sounds absolutely nuts for a game native to controllers!
I think as long as you ARE happy with controller there will be no issues navigating the GUI, etc, with a controller. It's just people who want good mouse support who will probably need to do some sensitivity tweaking and key rebinding to get things feeling like a proper mouse game.