To me this is not black and white.
There are times where I've given morphine SL PRN to a sleeping patient who did not request it and I don't regret it. PRN is up to my discretion too and I decided that they needed it for whatever reason and gave it to them.
If other nurses are telling you to give a resident something PRN when they are sleeping, ask why. Perhaps the resident is complaining or showing signs of pain every morning at 0800 or something. Or perhaps the resident said "I wake up all the time at 0200 with pain but I feel bad disturbing the staff."
If the person is hospice it's important, at least to me, to control pain or potential pain - so to me that would mean giving it even if they don't necessarily have pain. But if the person is on it for something else,
I think it's okay to wake them and ask if they are needing pain medicine.