I have no proof, but I have a feeling those who were approved to leave on 9/4 were already going to get cut.
I have seen many posts with people upset (understandably so), that their separation dates are in 2027. my guess is those in the later groups have positions that were not going to get cut. they have been deemed essential. I do not believe these people will be a part of a future layoff.
it does look like those in certain functions were given later dates?