The thing with the expanded media is that it's essentially 'licensed fanfics' - whilst you could say this about any media, the reason I don't take them as 'gospel' is because they can (and do) tend to change at any given time. Consider, once upon a time, the novels showed us a space jockey (not an engineer), Ripley, Hicks and Newt went on to fight for an alien infested Earth, etc etc... it took one movie to release... and non of that mattered anymore. What we are getting now between the RPG and the current novels are just the *current* EU canon.. Romulus could release next year and none of it might matter anymore, and it kickstarts a new cycle. The EU are just fun "what ifs" (in my opinion) to be enjoyed (or not, depending on the book lol)... but as far as I'm concerned, if it isn't in the movies, it's just fun speculation and interpretation on behalf of the author and holds no more power than our ideas and suggestions here in the forums. Remember, Colonial Marines was canon once too.. 😊