I think this is a really bad idea unless paired with some regime that penalizes inappropiate use of alarms - and most societies don't treat noise pollution as a real problem. For example, people honk all the time even when there are no safety issues. Or have misconfigured home/car alarms. Outlawing using ANC for blocking "fake alarms" only makes the problem worse.
I've recently visited the southern US (Texas, Louisiana and such) and I was very surprised about the lack of honking. When I returned to Europe I've felt like in India.
I myself pretty much never honk. I understand honking makes sense on narrow bendy roads like in the mountains, where you need to alert the drivers behind the corner, but I don't see any other legitimate reasons to be honest.
