If the spooks grabbed you while you were still at home in bed your stuff’d would be left behind, too.
So that is not a sure fire indicator of foreknowledge.
Thats true too. The problem with that scenario is that some of these people disappeared in the middle of the day and at least one that left most things behind had the foresight to carry a firearm which would be one of the last things a malevolent abductor would be willing to let someone take from their home.
At least some of them knew something. Im not entirely sure that all these things are actually related according to the present narrative so in reality there may have been several different things that occurred but really where is the fun in that version of the story?