I guess the practice of fishing over fish in a thermal refuge is something that varies by location?
For example, I've seen fish stacked up on the Beaverkill at the Acid Factory pool where Horton Brook dumps in many times during the summers when I lived in NY. Often there were several hundred fish just laying in there during the hot spells.
The mouth of slate run gets fished for sure. The other tribs on pine creek, not as much. It's due to the proximity to the hotel / wolf's general store and the fish that they put into the stretch.
Pine is marginal for trout survival in that stretch anyway. I doubt angling is a big factor.