My cynical answer would be: it never really mattered, so this is a way to allow new tech without scraping the whole idea. Especially given the number of possible radio bands and nobody publishing what the protested ranges were supposed to be.
Regardless of it mattering or not it is simply not true that that you cannot use them on flights, airlines actually announce that you can use them during safety announcements.
Some airlines make announcements, they are allowed on all airlines I have travelled on in the last 2yrs (when I started travelling a lot..)
I mean I don’t think I can prove that literally every airline does allow Bluetooth headphones, but see previous comments where the FAA approved Bluetooth headphones for use in 2013, maybe you could provide a specific airline which does not allow Bluetooth headphones?
