The FAI is all about "air sports", so I guess the question becomes, is a wind tunnel an air sport? Well, there is certainly air blowing around at high speed, but it's artificial wind, not natural. Does that count? If people could pilot aircraft in giant wind tunnels, would that be a valid air sport too?
For my dreams of FAI virtual reality skydiving, I guess I'm going to need a big fan blowing on me while I'm operating the computer software. That ought to make it qualify. After all, virtual reality is a simulation of real skydiving, just like a wind tunnel.