Well, I don't think the code is clear on it. Obviously if it re-installed in the bathroom then IMO you could not add new circuits from the panel. I think this is an AHJ call. IMO, if the panel is being replaced because it is failing then I would allow it to go back as long as new circuits are not added.
The question begs to be asked was this panel installed in the bath or was the area where the panel was installed converted into a bath? Essentially how did this panel end up in the bath.
I am also assuming this is a residence