@Lawrence of Arabia
We can only hope RS goes back somewhat to his previous plans, as Prometheus did offer a expansion to a limited Universe, and i feel in the ideas leading up to the Prequel where the Space Jockey race was explored as being Ancient Humanoid Genetic Engineers who played a part in the creation of Mankind and all the God Mythos and Religion that we have on Earth.
I think from Alien Engineers, FOX had felt the Arc of the Space Jockey was really interesting and so this is why they got Lindeloff in to concentrate more on this and tone down the Xenomorph because well, the Xenomorph was just to the Engineers what the invention of Gun-Powder was for us.
There is more to Mankind than just Gun-Powder Weapons and so indeed FOX saw there was more to the Space Jockey Race than just being some Alien Race who happen to have created a Bio-Weapon Xenomorph.
This Back-Fired a bit because a lot of Fan-Boys wanted to see Xenomorphs or at least more connections, and we also have factions of fans who are not happy with the Not So Alien Looking ENGINEERS and never mind the role they played in Mankinds History.
They had tried to expand upon the Universe by concentrating on the Origins of the Space Jockey instead of the Xenomorph, which seems to have not fitted in much with a majority of fans.
So AC was a attempted to now concentrate more on the Xenomorph, and to not dwell on other elements of Prometheus, but they could not completely ignore the Engineers or David, and at some point they felt it would be very interesting to make it that David is the one who plays the KEY role in the Xenomorph Origins..
A interesting move, one that expands on Davids line of thinking and the changes we see his Character has picked up from his Master..... but a change that while being a Curve-Ball, has had the same negative impact on a lot of fans as the Curve-Ball that the Space Jockeys were Humanoid Ancestors by DNA
The Franchise is so Split now as far as Fan-Base that its going to be tough to please everyone, we saw AC tried to please all parties but actually ended up disappointing to all parties, as far as not quite offering what each kind of fan would want.
This is where FOX/RS now have to think... do they give in to the so called Fan-Boys... those who wanted a More Alieny Connection to the Xenomorph and Space Jockey, and who may also want to see Queens and Ripley again...
Or do they go back and have faith with the ideas they had when they had finished Prometheus...
Its a tough one for sure..
I think the easy way for FOX would be to open up on its Alien Marketing Site a Fun 5 Question Questionnaire about the Franchise and Prequels with Multiple Choice... then they can gather Data to then Gage what Direction to take...
But then your not going to please everyone...
I think FOX may in hindsight, think the Xenomorph/Space Jockey Mystery should have been left at that... but then how can we just have had more sequel or parallel stories to Alien that deal with YES Xenomorphs... it would have been overcooked.
And so exploring the Space Jockey Race, and showing us the Experiments related to Xenomorph DNA so to speak, this opened up much more possibilities.
But i guess the reveal that the Space Jockey = Giant Humanoids (that ended up not so Giant) who go around seeding and terra-forming Worlds and played a hand in our creation... was just not to Alien not enough Gigeresque...
Then the reveal that by using the Tools that the Engineers had used to experiment and create Organisms/Bio-Weapons Related to the Xenomorph, a Human Created Robot.. David went MAD and used the Engineers Bio-Weapon to Create the Iconic Xenomorph.
I feel these could both be considered a error of judgement by RS/FOX.
But we dont have to go, all lets give fans a Alien 5 etc... I think they simply need to bring in a Race more Alieny who are above the Engineers and who posses very Giger Aesthetics and a Sinister Agenda.