This. The GoT producers are actually pretty bad, and got famous only thanks to the great source material. Everything they did themselves (more and more stuff after season 4) has been sub-par and sometimes even embarrassing (so much plot holes in the last seasons...).
Give them something great already written and ask them to follow it exactly, and they will do something good. If you tell them to create something, you can expect something pretty bad.
Can't do any worse than Rian Johnson did at least. I still can't believe that Disney is giving him a trilogy as well.
Hopefully they follow the source material from the Legends depiction of the Old Republic pretty closely, so that they don't make too many mistakes. The Old Republic era of the Legends timeline is one of the few areas of the old EU/Legends that wasn't a total mess, it was actually extremely good.