My T left me a voicemail once saying that I could actually come to the appointment she thought she had to cancel. I saved that message for months and listened to it over the summer when I couldn't see her. I did find it calming and reassuring during tough times because it's hard for me to conjure up the sound of her voice in my head. It was like she was talking to me. Then it got deleted somehow from my phone, which is one of the "possessions" I most regret losing in life. I have asked my T to leave me a message before I graduate, so hopefully she will! I understand feeling weird about it-- it is a little awkward since it's not spontaneous and it's a planned thing. But that doesn't mean it isn't authentic. Maybe after you listen to it a few times you'll like it, but if not, no harm.