I think it makes sense that the series turn-away from the basic formula for now. If nothing else, intentional or not, Scott's prequels proved that new creature developments were more interesting than the same old. I don't necessarily love the direction the story took, but for the most part, everyone seems to be in agreement about the inclusion of the alien in Covenant - it's the weakest part of the film. As happy as I was to see it, a certain reverence for it is MIA. Even with something great like Alien: Isolation, the creature is the least interesting part. The world building and the atmosphere was the real draw. Even the "working Joe's" prove to me that they need to add some developments to make it interesting again. The digital short depicted the aliens hibernating in space; that was a nice touch! This is also, unfortunately, not something I think the prequels achieved. They almost do but keep side-stepping committing to any interesting developments. It almost feels like they are doing so because they couldn't think of anything to add to it or weren't confident enough with their new developments.
Some interesting developments I noticed, which got sidetracked -
1. Egg morphing
2. Deacon on LV223
3. The Octopus-like squeezing of the xeno-body in the Engineers script
4. David experimenting on Shaw
6. Excretion of cocoon-substance from the alien's groin
7. The bizarre religious practices of the Engineers and cryptic use of the black goo.
9. Cave under LV426
I am also very concerned about Ridley's handling of the creatures. Its as if he forgot that the Alien should remain in the shadows and that hurt the last film most, IMO.
I don't think the alien itself needs to be marginalized, but I think the story needs to go somewhere else that captures the spirit while also not sticking to the formula. I can't disagree with Ridley that it has gotten tired.
The one thing I'll definitely give Scott for the prequels is that the series is definitely WIDE OPEN with possibilities.... for better or worse and in some ways both.
With the recent success of the Halloween and now Terminator franchises, both bringing back their iconic female leads, I'm personally torn between wanting Disney to involve Cameron and Weaver in a proper Aliens-like direction, and/or letting Scott further evolve it. I just hope they get someone in there to make sure the scripts can maintain that tense, suspenseful, entertainment factor. Both of Scott's prequels managed to build a great deal of suspense up until their key scenes - the medpod and backburster sequences - but then they both fall flat. I'm not sure how that slipped by in the writing/editing processes.