You're assuming that they need to actually control the noise.
True. The text of the bill says nothing about harmful interference. However, there is the implication that the receivers being mandated might actually work, and not just for the vehicle operator, but for the vehicle in the next lane as well.
The vehicles in the next lane can always slow down or speed up or change lanes to move away from your car if your car makes its radio too noisy, so that's likely to be a non-issue. I haven't measured the field strength from an EV to see if it exceeds those limits, though, so I could be wrong.
Note that the FCC allows AM transmitters up to 1705 kHz under section 15.219 without a license as long as the ERP is below 100 milliwatts and the antenna is no more than 10 feet tall. There's no transmitting antenna in an EV, so as long as the ERP is below 100 mW, presumably that qualifies. For frequencies above that limit, section 15.223(a) gives you a field strength exception, and given that we're talking about wideband noise, presumably no stricter narrowband limit should apply, so the limit is likely 100 microvolts/meter at a distance of 30 meters, which is, I think, in the neighborhood of 200 mW ERP. The stricter limits under section 15.209 presumably do not apply because it is not an intentional radiator.
That said, there may be additional rules that I don't know about, so take that with a grain of salt.