To be fair, IT IS true that we don't have enough evidence beyond reasonable doubt that Luke raped her. From the law standpoint, I understand the decision.
However I think they should (and probably will) end her contract. It's just too much of a mess for a big company like Sony and a big name like Dr. Luke. The public is on Kesha's side and with all the celeb support, it's not worth it for them to keep this going on.