Certain elements are, and others might not be, it’s “fuzzy” and I choose what details to accept for any number of ever-changing, ill-defined reasons.
Personal canon/headcanon doesn’t need to be internally consistent, it’s what *you* believe and makes you happy.
Internal consistency is something you’d expect from a broader “official canon” that you’re expecting everyone to follow - and is a big reason of why it’s a meaningless non-concept, and the AR novelization is a good example of why.
Even SM conceded that the novelizations should get cherry-picked as to what elements are “true” based on one’s personal thresholds for “contradictions” (the very definition of headcanon) and he cites the AR novelization’s crater size as clear proof that the Derelict is gone, going to far as to compare its number to the Nebraska example Bishop gives in ‘Aliens’. However that crater size doesn’t actually line up with the 40 megaton number that Bishop actually says.
Not to mention that he says novelizations shouldn’t be taken as “gospel” (because if you do, then the Space Jockey doesn’t exist
) but in the same breath he chooses to take the AR novelization as gospel.