It depends how the "10 years" is measured and from which perspective, although I doubt Ridley has put as much thought into that as with Interstellar movie.
It is also possible that space travel technology on earth advanced rapidly since the prometheus left earth. Meaning ships could effectively catch up with or overtake the distance the prometheus travelled in far less time and leave earth much later allowing for more time to pass along with tech advancements.
Or that the flying croissant ship Shaw escaped on, contained advanced messaging or navigational systems that allowed her to beam back to earth alien technology schematics for tech harvesting. While she probably doesnt trust Weylan as far as she can throw him/it right now, theres nothing stopping weyland corp intercepting such messages.
With covenant literally meaning alliance or agreement, I can imagine that weyland and yutani have separate segments on the ship, and then a common area where they collaborate. While the ISS aims to know no borders or politics, I can imagine if the covenant is in its early stages of a corporate merger, there will be a lot of office politics and one -upmanship bubbling beneath the amicable surface. Secret labs and tech and who knows what.
EDIT: I forgot to mention that although I think its more probable we'll see quite a hi-tech ship, I'm secretly hoping for a more mundane/relatable environment. I think one of the main reasons Alien ages quite well, is because greasy workshops and mining sites have not changed beyond recognition over the decades. Any environment which requires heavy machinery, oil, chains and pipes and a whole lot of elbow grease essentially ages well if you squint your eyes things never look too different or out of place.
Anyway, in the event of a hi-tech ship, I would really like to see mundane day to day events to give it an every day feel and draw us into the world of the movie even though its sci fi. I want to be sucked into the world, then devastated and thrilled by the unfolding of the story.