First let me intruduce myself: I am the creator of the hungarian AvP wikia and a huge fan of the franchise. I just noticed, that here the Timeline is missing a lot of years. For example I have mine: https://alienspredatoraliens-versus-predator.fandom.com/hu/wiki/Id%C5%91vonal
This don't have all the source materials, I still need to finish a bunch of comics, books, etc. but as you can see I have a lot of dates, that are written in the books/comics (Aliens: Music of the Spears for example set in 2223 and 2224), or Aliens: Defiance (2137 december to 2138). When I use the ' marking, it's means it's just a relativ date, the event happens around this period and I give clues why I think its there. Is there a reason why Xenopedia don't show these?
Sometimes the dates are relative hard to find, but they are there (for example Aliens: Rogue), I can write a blog post about ALL the books, comics, games when they take place, with sources why is xy set in year z. I am a bit bussy with the university and expanding my wikia, but I can help Xenopedia noticing missing things (weapons, events, planets). Like the Oil Wars, newly mentioned in the Destroyer of Worlds RPG but it's first mention is in the Aliens: Outbreak novel (altrough just namedropped).