The question is not if it is in-game footage, but if it is regular gameplay.
I mean if you look at the ED space flight / combat trailers, you will see various ships flying together, fighting, jumping etc. And when i say various, i do mean it.
IF you check
The Journey So Far trailer, 1:28 - you see a glimpse of a nice combat with Corvette, Anaconda, Cobra, Eagles, Adder and other. Not like you will meet something like that in game. It may resemble a CZ fight, but really vague and definitely not a PVP encounter where you will meet only FDL with the random Kraits/Mamba
Same goes for the fleet jumping at 1:40 - those are not normal occurrences (sure, a sort of similar jump happened probably in DW2) but really special events, not something that may be called regular gameplay.
Yea, FD trailers are really nice, but they're not really representative for something that will be normally encountered in the game.
That kind of combat footage i would expect to encounter in a UT/CS match, not in ED.