It is no coincidence that what the cast have been able to talk about is the Alien lifecycle.
Couples are important for three reasons :-
1) They are there to make a new life and have children procreate.
2) They will have a sense of mission and idealism.
3) They will provide the audience with immediately identifiable loyalties and emotional connection.
The first two will work neatly into the grand themes of the movies and the latter will give us our emotional connections.
Ridley is using the A L I E N prefix to make absolutely certain no one misses this is linked to A L I E N but that places him in a position of expectation. He knows the beast is cooked he made the point as recently as February and called AVP silly. So the A L I E N will be a weapon in real life an anchor for the audience to get into the cinema. He then needs some scenes which will be endlessly referred to just as the original was but the real success will come from the reaction of Daniels and the crew and their desire to survive so we are willing someone on to the end. He got it right with the Martian he is on form.
A L I E N was also about what we did not see I am sure he will hold on that, avoiding the two mass killings of Prometheus which rather to neatly and without mystery got rid of the crew. I do not expect him to have to deal with an awkward transition (Sir Peter) so late on in the film which meant the focus changed just as the movie was about to resolve and fly; the third act of Covenant may have more of the relentless feel of A L I E N S.