It is hard to change Ts. My just up and told me that she was leaving and I met a new one last month. So, I would say that worse case scenario would be the new T reviewing the sessions from the past for a while. My new T basically reviewed the first session and did an orientation. I suspect that is what might happen to you. I suspect my old T and new T can still talk because they work for the same agency. I do wonder if you could make it so that they can talk. It is rather hard to explain what you said in the first session when the T references a note from the file to you. I just can't hardly do it and it had only been three months. I hope it all works out for you.