Field Report is technically an Aliens: Fire and Stone tie-in short story, a small apart of the complete Fire and Stone which is an AVP series, not a canonical Aliens series.

@SynthNorbert but this is the Alien vs. Predator wiki, and things like the AVP movies that contradict films like Prometheus do not have the non-canon format. The rest of Fire and Stone/Life and Death also do not have this format. Maybe I'm misunderstanding, apologies

No worries! Personally, I am not a fan on the non-canon header because, you're right, this is a fully inclusive AVP wiki which takes all three Alien, Predator & AVP continuities into consideration. I think the non-canon headers should at least be revamped, so there are three, one for each licensed property. But the short answer is because within the AVP or Alien film series, these titles have not been established as canonical, only EU. At the end of the day, Field Report might recreate a scene from a canonical film, its part of the AVP series, not the Aliens series, which is why its listed as non canon. I know.. its confusing. But have no fear, you put it wherever you want to in your own headcanon!