If they intend to do some wuxia with the kung-fu, that means wire-fu. But in the trailer it doesn't look like there's much of it. Not sure how much of the slo-mo is CGI, but in general it seems like genuine martial arts. Dunno how long Simu Liu trained for this (does he have martial arts background?), but here's hoping it was more than Iron Fist.
Fun fact: Apparently today is Simu Liu's birthday. So a birthday gift to him and to us.