Why do you inherently trust what SpaceX says? I'd rather NASA or other outside agency conduct their own tests to be sure.
It's not really different from when SpaceX starting landing F9s at the pad. I worked in the industrial area at CCSFS for a decade; the first handful of pad landings required full evacuation of that entire area, but after they proved success then it stopped being so broad. I see no reason to expect a different outcome here.