I just have a difficult time with how much this could retard growth. Every film in the series other than this has at least tried to be uniquely, tonally different from the last, trying to do and say different things within the existing framework - even the bad sequels do that. This, OTOH, sounds just like a riff on Aliens with the old favorites, doing more Neill Blomkamp shoot-up-the-Weyland-Yutani-baddies fun, just like his other films, which have had diminishing returns. Maybe Jodie Foster will even return to affect a terrible accent and demand that her stormtroopers kill Ripley before she can destroy the alien eggs. I just don't see what this approach could bring to the table that's new, beyond how lovely it would be to have Sigourney back.
This is what sank the Terminator franchise, first with the show and then with the films, to say nothing of the wretched Terminator 3. They keep trying to paper over what was a natural endpoint with loops within loops of time travel and it just gets sillier each time.