But the interference has ALREADY occurred! The Commander In Chief has ALREADY said that Bergdahl should be convicted and executed. Article 37 says what commanders must not do for a fair trial. It does not say what jurors must do because it assumes they will follow the wished of their commanding officer.
Now he can't get a fair trial so a request for dismissal is not some stunt. It's very likely going to be granted.
Personally, I would have liked to hear the evidence at a fair trial. I really don't know enough about the case. It sounds like he was only guilty of going for a short walk (which I am sure soldiers do all the time) and everything that happened after that was not his fault. But I doubt a fair trial can happen now.