Citation needed.

Too many lawyers, too many bureaucrats and too many regulations. Killing everything interesting as usual.

Doesn't specifically state pop-up headlights but here's some interesting info: Taking the Hit: How Pedestrian-Protection Regs Make Cars Fatter - Feature - Car and Driver

On my Volvo S60 they redesigned the wipers and hoodline in 2014, the wipers are under the hood edge which basically guarantees they get clogged with snow very easily and become useless. When I complained to my dealer they told me that design sucks and Volvo knows it, but it was a compromise to meet pedestrian safety laws around the globe.

The upshot is these designs probably make it safer when one hits a deer or large animal at speed, much more likely for most of us than hitting a pedestrian.

Regulations are why cars are starting to look all alike.