What about Katadhin Woods & Waters Monument in Maine which Obama created? It was a donation to the feds where the previous owner was actually slowly limiting access in general, now it is open to access and hunt in most areas.
I believe you answered your own question there. It wasn't a change in Federal land-land status. This thread isn't about land donated to the Federal Government.
Castle Mtns is under the NPS which of course most areas are closed to hunting.
The difference is Castle Mt is BLM land that allowed hunting (and does again now)administered by the Park Service. It is not Park Service land. Key distinction. Only Congress can change the land status, monuments are a layer of management