There are no laws or even FAA regulations that require airlines to enforce mandates to wear masks on flights. Rather, they obey arbitrary "guidelines" issued by a questionable quasi-federal agency, the CDC.
Technocrats can flip-flop on their scientific crystal ball just as fast as any carpetbagger politician can read the political tea-leaves. The only reality they acknowledge is their own, and their goals justify the means to achieve them.
Regardless of your understanding of the Great Panic of 2020 (COVID-mania), there is little doubt that it has seriously messed with everyone's psychological, mental and emotional states. Disjointed thinking, fractured reality, Hegelian Dialectic, group-think, etc., are hallmarks of today's world.