Im kind of excited, but not excited about the Ampules. If they are to make an appearance in covenant, why not make them have tubings coming out of them or something that looks a bit more veiny/mechanical/Gigery and less reminiscent of Prometheus if the movie title is deliberately more in the Alien direction?
The Ampules work so well in Prometheus because of all the sleek styling and aesthetic. It would be more interesting to see a re-engineered (by David?) Ampule design. Like an Ampule with what appears to be a pulsating tumor coming out of it or something. Part sleek and beautiful, part grotesque.
Still, the planet could be a seeded planet where the engineers dropped a few Ampule bombs, and thats all the crew come across - a few broken open empty Ampule halves amidst lots of lush greenery and seemingly idyllic surroundings. Since the engineers wouldnt do that to their own planet, maybe they stuck around on a nearby habitable moon and watched from afar as their testtube planet evolved. During one trip between planet and moon, the engineers bring back something which wipes out their moon colony. The pompeii looking massacre is what the crew discovers on the moon, before they continue to the planet up ahead.