FFG almost certainly didn't know what it would do in the film. They knew a name for it (and not a final one at that), a combat role, and a design/model, plus some generic squadron names.
I'm really starting to wish they didn't have to do tie-in releases. EVery single one to date has been at best mediocre:
TIE Striker: reasonable, fairly well balanced, interesting, but immediately murdered by the metagame.
T70: All overpriced until HotR, and even then, still needed another fix card in FAA to really work.
TIE/fo: exactly one decent pilot, maybe two now that Advanced Optics is out, and again, got crushed by the changing meta.
U Wing: just lol.
TIE Silencer: overpriced, probably. I struggle to believe that 40+ points on a ship with 6HP and no regen is going to work long term, it's in a similar (but not quite as dire) position to the pre-buff Defender. And missing the missile slot is irritating.
Resistance Bomber: remains to be seen - I suspect Trajectory Simulator will be stupid good, but will be the only thing in there that is - especially because there's very little in the set that's usable outside it.