It's seven knots, over the whole course area, a little too low IMO.
I'm kind of torn on minimum wind strength.
On one hand lighter winds are the lighter guys time to shine. Being something of a stick myself, I can tell you watching the bigger boys come tearing past in 20 plus knots of wind is about as much fun as I can imagine watching stick man sail away from you planing in 12knots
On the other hand, slalom's meant to be fast and action packed. The less wind there is the less action there is. I think for the larger part they've got a good formula in PWA slalom, in that you can change sail sizes to suit wind strengths. 7 knts is pretty ambitious though. I'd hate to have to float around a course, balancing a 9m sail all the way.