The answer is partly yes and partly no.
Yes blind athletes were proven to do the same victory gestures than normal people (there is an experience somewhere here but I can't recall where). So some of the body language is instinctive. Basic facial expression are universal, I wouldn't be surprise to know this applies to those too.
Another thing is linked to the culture. You don't count in the same way in different countries, some gestures can have different significations. Those non-universal languages can be learnt IMO.
A third thing is linked to codes. Divers, militaries learn gestures they use as part of their job. This is still body language, but since it is codified, it is learnt.
So I would say that the base is instinctive, while a more evolved version is learnt.