Well, the configuration changes during takeoff mitigate the issue if it happens during takeoff. If it happens at any other time then they don’t do anything to help.

> I can see no reason to drag feet on this recommendation […]

I can. Perhaps the FAA believes that it is better to minimize change fatigue. Since the problem can apparently be fixed in software, and Boeing has decided to make that fix, they might want to write just one airworthiness directive requiring everyone to install it instead of two, one telling pilots to adopt some procedure followed by another telling them to abandon it.

> (It is yet another difference from older 737 design , like the deadly MCAS system, that was not disclosed to pilots transitioning to the new aircraft)

Keep in mind that for most aircraft the airline can pick and choose between different engines. The pilots don’t have to learn the myriad different engineering decisions that go into those engines; from the pilot’s perspective they are supposed to be interchangeable.