No, and I would say that just because they don't fall under a definition of the human rights...as a human rights defender doesn't necessarily mean that we're not advocating in other ways.
If I may first answer your initial question, I don't think we would be opposed to including the subcategory of “prisoners of conscience”. It's not out of disliking the term. It's very much, as I said, to go much wider in scope.
The example you just described, in which an individual is peacefully standing up for rights regardless of, in this case, the right to the freedom of religion or belief, we would consider that to be a human rights defender.