As mentioned, this isn't a Boeing-specific issue. This affects every major aircraft manufacturer, as well as a lot of smaller aircraft with aftermarket avionics. Surely Boeing isn't going to pay for the entire industry.

Also, the FAA has no way of knowing if a particular aircraft operator is using a radio altimeter or not. Even if I have one installed, maybe I chose to switch it off. It's also possible I'm using it for situational awareness only (which is still allowed) and not using it to descend below legal approach minimums.