I was there at 21th of June 2015 and saw no signs that said it was prohibited to fly, I did see a little wind vane, so I would say it is "open for business"
Today (26-07-2015) climbed the hill. The two men were flying models.They informed me that very often they see here paragliders taking off and flying over a hill. The approach is tiring, but worth it. There are parking lots. Moreover there is some paragliding school, good idea to find and contact them.
What a cool hill in the flatlands of Belgium.
Park on the parking place on the Oude Tuinwijk (near the Holenteerstraat)and walk/hike up into the woods into a northwest direction and get the wow effect when you clear the woods.
The area is supposed to be private, but the owner (I do not know who it is) permits such use. The area is accessible to the public. I've seen whole families and youth getting for a camping.