The best way to protect a site is to leave it alone. If we start finding dozens or hundreds of sites it will be more than what archaeologists can excavate and protest. Treasure hunters and looters don’t care about stratigraphy and the processes involved for doing research. Maybe the cat is out of the bag on this one, but good for thought.
Edit: I’m not saying we shouldn’t have people use AI to do this or that no bad actor will. This comment is in response to the sentiment I am seeing in the comments that we should lidar the whole world and have AI find any anomalous structures it can. There is no way for archeologists to excavate and protect all those places in that scenario