I probably will do a post on this next week actually, I think I could probably write a thesis on the Alien universe at this point!
Yeah absolutely, and not only were the engineers killed off in it, they had seconds of screen time. Covenant didn't add anything to the mythos or story, I think Ridley Scott kinda choked on this one, letting the intense criticism from Prometheus affect his vision. I'd not really thought about the killing scenes, but you're right. They were just pandering I guess, trying to attract the box office audiences, but we were just left with an inferior film. In retrospect, I've been far too lenient with this one. Films like 3 and resurrection get somewhat of a pass for their cheeseyness because they weren't directed by Ridley Scott (or James Cameron). They were obvious cash grabs, crappy additions that the executives wanted. This was a Ridley Scott film, and in that respect the film completely failed.
"Apparently", the next film will be far more engineers-focused and less xenomorph. Hopefully Scott can redirect this franchise back to his original vision and join the prequels up with Alien in a satisfying way. Why is the Space Jockey so much bigger than the engineers we see? Why did it appear to be fossilised? How did the derelict get to LV-426? Why did it seemingly have a cargo of xeno-eggs? Is David the original creator of all xenomorphs, or just the neomorphs? If the engineers created us, who created the engineers? Sooooooo many questions still need answering.