So the new alien film MAY be taking place on the Engineer Home Base Planet. But David and Shaw got there first and met the Engineers and that final shot before the trailer started showing David overlooking all the engineers looks like he may just unleash the Alien Plague upon the Engineer Engineer planet either accidentally or on purpose...or maybe Elizabeth Shaw does it out of revenge?. Then Alien Covenant starts and the human Colonization ship comes and that's why the planet is so empty.
Just a Guess!
(New Shot revealing the Engineer Homeworld!!! :O Its like an Anunaki Homebase or like an Ancient Lyrian city! )
But I actually believe its not that simple and alien covenent takes place on a totally ifferent engineer planet and this clip showing avid and Elizabeth arriving at the Engineer Homeworld with thousands of engineers all running out to the "city main square" landing pad to see the ship from the bio weapons planet returning.....this is all a clip from a THIRD movie or Prometheus 2 or basically the sequal to prometheus....
So yeah this amazing clip may just show David unleashing a plague upon the engineer homeworld LOL