Haven’t heard that before. Regardless, in most cases it’s almost certainly overreach and over-reaction.
Where I am, at least according to the EPA consolidated list, the only regs listed are for diesel vehicles, attended or not. It’s pretty clearly aimed at preventing drivers of the big OTR tractor-trailers from leaving their main engines running to provide heat/power while they sleep. There’s no mention of gas vehicles at all, which is what I have.
No doubt in some of the more Blue (i.e. “nanny”) states, the laws prevent anyone from ever running their car unless they’re actually in the driver’s seat and moving.