Is this potential compatibility loss a real issue ? 

AFAIU, it may be, but should we miss the associated benefits ? I don't think so.

I agree here, after all at the moment we need to introduce any parameter translation for realistic values we are losing some compatibility, which everyone seemed to accept in the last meeting. I also think losing compatibility is just a matter of time.
I have no idea of how hard it is to introduce wind support in Simu V2,

I think a simple model is just a few lines, like this:
1.) {velocity used for aero}= {car velocity} - {wind velocity}
2.) use the longitudinal component of {velocity used for aero} like now
3.) {side force} = {horizontal component of velocity used for aero} * {side-wind coefficient}

So it is basically two additional lines and one new parameter, but of course {wind velocity} has to be set somewhere else (probably in the race engine), and robots should be prepared for win, etc.
but assume we'd also have to make some changes in other places
(GUI, race engine ?) ... and these changes are not in the 2.0 roadmap
for the moment.

I think I will just add it and then comment out until it is needed.