I could argue that jet packs and flying troopers absolutely would not and should not be a surprise to these people…but whatever, right? It’s f*kin ROS.
I saw a meme template which someone did and honestly it would have been a better exchange:
Finn: They fly now?
Poe: What, have you never seen a jet pack before?
Finn: I didn’t say “What’s that magic flight-granting box”, have you seen any jetpack troopers in the First Order before today? Because I didn’t!
It was a meme template but honestly it would have worked better as a panicked, seat-of-the-pants dialogue exchange.
They should just say “they fly now?” once and that’s it.