It seems unlikely to be a foreign power because when they left they didnt take important personal items and things that could be easily tracked. It seems unlikely that an assassin or alien would make someone leave these kind of personal items behind.
Im pretty sure that at least some of them knew they were going somewhere and were picked up most likely by us.
Do you remember that Trump refused to renew that treaty with Russia? Everyone was focused on missiles but it also covered some elements of satellites. The recent advances in our weaponry have been in DEWs especially radio waves and focused lasers and thats just what they have admitted. Starlink is just the first leg in a multi layered plan with Mukt looking at space born communications with focused lasers, and besides being used to protect themselves from electronic threats like enemy satellites, a focused radio wave would allow a proposed halo of satellites to transmit energy from space born solar plants.
All of this ties in with the issues with Svalbard and Trumps need to acquire sovereign land in Greenland because there have recently been problems with access to the communications on Svalbard because of changing terms. If we had a piece of Greenland, even a base that wasnt leased or or had its existence only determined by the whim of Greenland/Denmark, then we could build our own system and never have to be concerned with access.
Why would a foreign power want the victims to bring along things that could be tracked or would be traceable?