I wouldn't have put Medivh or Sonya at the front of the queue when it boils down to whether or not both needed reworks. However, it's evident that Blizzard were unhappy with the state of both when it comes to build diversity, or viability. The changes on the PTR have seen significant changes for both, and while their gameplay remains inherantly the same, they've both got a little bit more build diversity. 

You can read the full PTR notes here.