The same technical fixes were proposed for cameraphones in the late 2000s - lights, shutter sounds, etc. Most phones in that era experimented with various implementations, but pretty much all of them were easily defeated.

As you say, the real solution is to make it socially unacceptable to use them in public places. The appropriate tools are banning and shunning, not lights and sounds.

I believe regulations in Japan currently prevent disabling the camera shutter sound in order to combat privacy invading photos being taken, so this still happens in some places.

Of course, those devices aren't made by a company whose sole purpose is the total and utter destruction of privacy, which is where this idea perhaps breaks down for the Ray-Bans.