I believe the new 787-9s will have Bluetooth. But they’ve not begun deliveries yet.
The thing with Bluetooth is battery life. I’m lucky to get 2.5 hours out of airpods when watching movies on a long flight. I question how useful it is going to be on the types of long haul flights these planes typically fly.
I get 17-18 hours out of my Bose NC 700s, and they recharge for a few hours of use in just 10 minutes or so (i.e. a bathroom break). I don't really watch stuff on the screen (I usually just play the flight map) but I can't imagine buying earbuds that need to be charged every few hours, what a pain!