I look forward to what the new movie brings, and seeing what Hawley ends up doing with his tv show too. But if I don't like them, I certainly won't let either of them detract from the way I view the original movie, that's for sure. I just won't bother re-watching them if I'm not keen on how things pan out, simple as that.
No matter what Ridley or anyone else involved in this franchise comes up with retrospectively, my own ALIEN 'mythos' will always retain the mysteries that were in place when I first watched the original movie - where alien eggs of unknown origin were discovered along with the skeletal remains of a larger alien of equally otherworldly, mysterious origin. A self-contained cinematic classic, which left those particular questions unanswered, and was the more unsettling for it.
ALIEN (Theatrical cut), ALIENS (Special Edition) and ALIEN 3 (15MaF's fan edit of it, at least) make up my own preferred 'canon' where Ripley's journey is concerned when it comes to a re-watch, while I completely ignore ALIEN RESURRECTION and the AVP storylines altogether nowadays as merely being 'Elseworlds'/'What If?' kind of scenarios.
And I consider PROMETHEUS and ALIEN COVENANT as yet another couple of 'Elseworlds'/'What If?' storylines too, due to my disliking Ridley choosing to turn the skeletal remains of the 'space jockey' alien into a 'spacesuit' contraption for a humanoid 'Engineer' instead....and having a human-created android create the alien using 'black, magic goo'. Neither of which I agree with. At all.
While I really dislike how ALIEN COVENANT turned out, there's enough elements I happen to like about PROMETHEUS itself to give it an 'Elseworlds'/'What If?' re-watch in future - there's a couple of decent fan edits of it available which improve things for me, although I'd want to re-edit things in a specific way for myself to delay the introduction of the Engineers to keep their appearance a mystery until later in the movie, and expand on Shaw's fate to give the movie a more complete, self-contained outcome overall.
So after the initial 20th Century Fox title and fanfare, my ideal opening would begin with younger Weyland's TED talk, and as the sound of his audience fades, I'd continue directly to the Prometheus ship travelling silently across the vastness of space as we are eventually introduced to David and the rest of the crew soon after. I'd make other individual trims to improve some of the dodgier moments along the way, and I'd also include certain deleted scenes too.
As far as the ending goes, I'd want to have Shaw and David fly off for the Engineer's home planet with her warning voice-over as usual, as we then see the birth of the Deacon before it roars in close-up as we fade to silence....except this would then be followed by a re-edited version of the 'Crossing' footage as we then see the Juggernaut travelling in space and hear David's voice-over describe their progress, as we then see Shaw re-attach his head, then set course in the control room, then put Shaw in hypersleep, then stalk the ship as he says "And then I was alone again....I learned of their ways and awaited our arrival...." Then I'd cut to the entire sequence in COVENANT showing the ship arriving and David dropping the 'goo bombs' on the writhing population as we end on him saying "Look on my works ye mighty....and despair...." At this point, I'd then conclude things with a shorted re-edit of the 'Advent' footage showing what happened to Shaw - so some interference static would crackle, as we then hear a female voice say "Weyland Yutani protocol sequence initiated....commence transmission", as David contacts the company with his description of Shaw's horrific fate and what he's been experimenting on for a long time....and I'd end things on the footage of something slowly moving inside an open egg as we hear David say "It took years....but I finally found my wolf....", before cutting to blackness as we then hear him announce "....My creatures shall be let loose....to rule this galaxy!", as the transmission static breaks up and the Weyland-Yutani Corp logo briefly appears with the words 'End Transmission', as we then briefly see a close-up of David's eye, before the static interference cuts off to silence.
So yeah, I could go with simply imagining that this unstable David has 'somehow' been capable of contacting 'the Company' at the end of PROMETHEUS instead - not to 'offer an olive branch' to them, but rather declaring that this is the way that things are going to be now!
By 'extending' the end of PROMETHEUS in the way I've described above, the 'Crossing' footage/dialogue allows a way for me to actually SEE Shaw re-connecting David's head back to his body, before piloting the Juggernaut together. And by adding the complete 'goo bombing' scene from ALIEN COVENANT, I also get to see what the Juggernaut is capable of, as well as what the Engineer's 'Paradise' home world looks like, without watching the sequel. And most of all, I still get to see Shaw's storyline wrapped up - she died 'offscreen' in ALIEN COVENANT anyway, and the 'Advent' footage/dialogue gives things an even sharper edge to her fate....as well giving a little more insight into what the 'black goo' is.
For those that readily embrace Ridley's prequel ideas, then you at least have the mystery of the 'black goo's actual origin to ponder I guess. That, and the headscratching question of why the stuff seems to produce such inconsistent results throughout both movies! I'll just look on it as being a totally unstable and unpredictable substance from moment to moment - so the effects of it's use will always end up varying wildly, no matter the amount involved.