It was meant as a way to force an interaction before the individually tracked units update, where you couldn't find people out in the open. Now that you are able to go out and find them manually, it presumably made no sense to keep the button functioning.
I would prefer if it was taken out entirely and the hypnosis events were also tied to pawns, specifically happening more often with pawns that have the 'Hypnosis (hypnotist)' fetish.