Not saying that they will make all the marines from Aliens either, but the actual tweets were about the ACM game and not the movie:
tweet: "what are the chances of us getting all the colonial marines figures?"
Randy: "Slim to none"
Tweet: "why?"
Randy: "The actual marines don't sell well enough, especially ones from a game barely anyone knows"
Tweet: "what about xeno's from the game?"
Randy: "Maybe some Xeno's one day from ACM but not anytime soon"
Whether the very first tweet was really about just the ACM game or all marines in general, Randy was definitely replying in regards to the game and I think we all know that there's 0% chance at getting every single marine from the aliens universe, for a start who would want that!
So I'm guessing all the people who really only wanted the movie characters anyway, shouldn't be bothered about these tweets, as there's no new info we didn't already know.
As far as it stands there's still a chance we could eventually get most if not all of the cast from Aliens. Granted a pretty darn small chance but better than "Slim to none"