It’s also the fact that if everyone stops using AM, the RFI pollution from EVs and other tech will balloon even more than it already has. Those frequencies are used for a lot more than just emergencies. I’d bet the push for this came from the military or the FCC.
If standards aren’t set and enforced for that shielding, it won’t just be radio in cars that don’t work. That RFI travels like a tiny broadband (as in multiple frequencies) radio station… because it is. The impacts are compounded the more cars are like that.