They did invite her to the launch event but then told her not to bring the Truckla. She did a funny video looking a bit baffled at the event. They should have let her drive it on stage before the real thing. That would have been funny and I'm sure she'd have been up for a stunt like that.
I don't think Tesla needs to license her design as there is no trademark or patent. They can start manufacturing mini-pickups any time they want to. They probably aren't because the market for small electric pickups with miniature beds is a small one. The direction they are going seems like the right one to me; big, powerful, featured, luxurious vehicles that absolutely out-class ICE vehicles and leave us wondering why we spent a century going the wrong way, is the correct market to address. Musk being a dick driving around LA in his hulking machine is also correct and brilliant marketing.