Well, as usual, i disagree with just about everybody. I thought it was a thoughtful, appropriate letter. I would not want a robotic "official" heartless goodbye. I would want acknowledgement of where we had connected, where the client had reached out, which is what i think she did.
Also, where is it written that a t must never express a personal emotion? I dont want my t blurting out, "boy are YOU dumb!", but thats different from them offering a considered opinion. Thats all we are promised from them, that they will think before they speak. Not that they cut themselves off from any feelings. Those feelings are a tool used in therapy, which is a personal, human relationship. Otherwise you may as well use a computer.