MMO = Massive Multiplayer Online Game, right? Why would such a fighting style make this less a community based game?

Either I lack of creativity or I have too much at this point but I can't see why the dynamics in the vid (jumping, combo fighting (close contact, weapon, spell), environmental incorporation) make something less an MMO, a game where people play together that is. Not talking about the technical issues but about the system itself.
Whether I target a mob and hit a weapon skill to activate a kick or wether I "combo" a kick, isn't that rather a difference of control than of genre?
Also right now I can't imagine why this should inflict party play. Like I said, to me this is rather a style of controlling your commands and interacting with the surroundings. :x
Sorry for possibly being so foolish but like I said, I'd love to have these open dynamics, yes also in parties.


On a site note: I'm not seriously begging to get this int XIV. I know we won't have this kind of combat system, it's rather a question that leaves me wondering in general.