It’s not new and that strategy doesn’t always work. I tried to get a hotdog in SF in like 2014 and they wouldn’t let me through. When I asked about purchasing alcohol he said that was allowed but they would have an employee escort me to the liquor and then checkout to ensure I couldn’t go to the food court.
I've used the ATM at that Costco and nobody followed me or nagged me. But that location is right by a bunch of good places to get food so I've never tried to push my luck.