I'm not sympathetic to the airlines right now.
maybe the airlines should temporarily reassign the teams that redesign seating arrangements to reduce spacing to allow more people onboard. they seem very efficient at their tasks, and there's really not much left for them to do
The FAA waited until December to issue airworthiness directives that limit the ability of the airlines to rely on radar altimeters under certain circumstances. The background here appears to be some kind of pissing match between US government agencies including the FAA, the FCC and the NTIA.
What exactly do you think the airlines were supposed to do here? Go out and have all their radar altimeters replaced? Replaced with what? The required standards haven't changed, and it's the FAA that writes the standard (technical service orders).
This is also not a "smoke testing" problem. This is a "on the worst day, in the worst set of circumstances, what is the degree of compromise of the assumed safety margins" question.