This prediction of a false flag alien invasion goes back at least to an alleged Werner Von Braun claim and has been doing the rounds for a good few years that I am aware of:
My own feelings are that since 9/11 it is clear that there is no end to the layers and levels of deception that the powerful will employ. There are possiible scenarios and possible agendas and endgames and possible perpertrators. When I try to see this through as a thought experiment though it will need elites in Russia and China as well as the US to be included in the plan. Ironically, in my opinion this would need to be orchestrated by one of the ET groups.
All I can see at the moment is that some of the human elites believe that this planet will cede to them if they can wipe out most of humanity and retreat to their bunkers for a decade or so while the dust settles. Bunker building has reached epidemic proportions amongst the wealthy. They may well be thinking that a greatly reduced population will allow the ecosytem to recover for their families' personal enjoyment. They will need to take new tech and AI with them and to have a secure alternative enrgy source to keep them going while they wait to emerge again.
Are there collaborating elites mad and bad enough to reduce humanity to just enough for their needs - say a few hundred million? There is an idea circulating that there are too many of us. You hear people say it now as if it must be the case. If you try to probe the thinking behind this you will not get very far.
We could look for signs of preparation for such a scenario.