I see a few key patterns here. First, the decision to first block, and then allow, green card holders was meant to create chaos and pull out opposition; they never intended to hold it for too long. It wouldn’t surprise me if the goal is to create “resistance fatigue,” to get Americans to the point where they’re more likely to say “Oh, another protest? Don’t you guys ever stop?” relatively quickly.
Especially if combined with the DHS and the FBI, which appear to have remained loyal to the President throughout the recent transition, this creates the armature of a shadow government: intelligence and police services which are not accountable through any of the normal means, answerable only to the President.
That is to say, the administration is testing the extent to which the DHS (and other executive agencies) can act and ignore orders from the other branches of government. This is as serious as it can possibly get: all of the arguments about whether order X or Y is unconstitutional mean nothing if elements of the government are executing them and the courts are being ignored.