The more I think about it the more I feel this is indeed a checkup to see who is loyal and who needs to be long removed before the upcoming midterms...

I can't remember a full on recall of all world wide command staff before a small conflict is started, so this definitely has an ulterior motive.

It might be an innocent event/meeting in itself but behind the curtains they will investigate who responds how to this summons. Perhaps they'll even brainstorm a reason for it, like a military intervention in venezuela, or "we attack the UN" ... perhaps it will be "we occupy gaza" ... or who knows "boots on the ground in Ukraine!" ...but ultimately it will be a loyalty investigation.