Echoing what
@Ned Flandalorian said, it's definitely not hostility they react with if you have Meta Alloys on board. I need to update my reference video, but in a standard encounter with an interceptor, they do not react with aggression at all, rather, they have a unique reaction that is best described as Friendly, Submissive, or even fearful in a way that excludes aggression.
I'll explicitly note; the only reason the interceptor deploys the swarm at the end is a separate trigger to do with being within 500m of the Thargoid, as the MO of Interceptors at the time of that now-5-year-old-video (which echoes my concerns somewhat) was, if you had cargo of interest (be it Guardian, Thargoid or Meta Alloys) to stick within 350m of you... so when the "cargo of interest" phase stops, the "within 500m reaction" immediately triggers.... thus I have to update the reference video.
This is unique compared to the others, being (links included for direct contrast):
Thargoid Cargo: Much more like "stolen cargo", stern warning followed by aggression if you don't jettison, but avoid aggression if you do, and they'll scoop it up.
Guardian Cargo: Much more like "prohibited cargo", outright anger followed by aggression if you don't jettison, but avoid aggression if you do, and they destroy it.
There's also a unique reaction for grelics, which they react to like Guardian tech, but scoop up. There's more info
in this thread I wrote back in 2018, but have kept updated with stuff like grelics and an exhaustive list of reactions, stuff about Thargoid summoning etc.