Nothing specific yet, but the legal groundwork has been laid both in the US and in the EU. Starting in July, all new cars sold in the EU will need to be able to fit after-market alcohol interlocks. In the US, interlocks are already mandatory for convicted DUIers in most states, but new cars will also have to come with factory installed drunk driving prevention technology in the coming years. We just don't know how far that mandate will go eventually.

There is no proposal to require these janky ass aftermarket units, nor require any type of interlock at all.

NHTSA was directed to write some guidelines/rules around the implementation of passive impairment detection as OEM features. They have yet to do so, probably because it is flaky technology.

My guess is that the final rule implementation will be similar to the distracted driver detection that is already in many new vehicles.

Old cars sound better and better every year now.

Not really the same. There are proposals to require OEMs to install driver monitoring, but it’s usually IR camera based rather than blow in a tube fuel cell based. These systems are probably going to be a mess but the technology isn’t really comparable to DUI interlock devices and the unreliability of those systems is orthogonal.

No, the 2021 infrastructure bill required automakers to install passive technology (passive meaning not requiring any specific actions from the driver) to prevent drunk driving by some future date. However, such technology doesn't really exist yet.