Haven´t been there since 2015. Some non kiting friends still there. They told me that the beach access has been restricted by Saudi Aramco, since they are building/expanding there constantly. Just looking at the google maps satellite imaginery and have to say that a lot has happened there in the last 4 years!
This was my go-to place at the time https://goo.gl/maps/5sFSVgPmqHp
. Apparently this area with the lagoon down south has been restricted.
This lagoon was another gem: https://goo.gl/maps/cFrB8k3MrmS2
Go there with a 4x4 from wherever you can reach the seafront, based on the sat pics that area has remained more undeveloped. I used to drive first here https://goo.gl/maps/NXfdcJomGnw
and then head north from the beach, not sure if this access point is restricted, looks bad from the image. Luckily you can drive trough the desert from somewhere else.
If your up for a drive a bit further, this spot was very nice, with some actual facilities as well https://goo.gl/maps/cmWcKky3rDP2
Season wise I was there from september to april and pretty much for that whole time there were good winds for a 12 m2 kite. Based on yojimbo´s link in the beginning of this thread indicates less winds for the summer period...
Here´s an edit from the spots
Good luck, hope that you get to do some kiting there.