Judging from the fact it doesn't say anything like area, or AOE in it and only says one strike, I'd say it wasn't intentionally made for AOE.
But I think we will allow it, should be fine. 

But I must say, I haven't been paying much attention to sword skills, but I would prefer, not sure about Caits, if you don't use anything other than Tsujikaze, Gengetsu and Ukifune for now. I want to discuss this side of things more with Caits. Probably need to design a few more sword skills to be available as well.