Not sure how reliable this will turn out to be, but I can't say I'm that surprised:

It wouldn't be shocking, but rather expected. Because we should see some departures from the Cabinet.

Because the Democrats took the Senate, Trump will have vast difficulty in getting his nominees confirmed in the new Congress. He'll especially have trouble getting the sorts of nominees he likes. If Trump wants to make any changes to his Cabinet during the rest of his term, he'll strongly consider making them now, so that the new nominees can get confirmed in the lame duck rather than after January.

I expect the message has gone out to the cabinet that anyone who's considering leaving should let them know now, so that they can get their replacements in before year-end. It's actually pretty rare for a cabinet member to serve four years - it's a hard job and most will leave before that - so even apart from other considerations, many of them would be past the halfway point of their service anyway. And the next two years are going to be a lot less fun for any department head than the last two. So I think we can expect at least a few high-ranking departures. High on the list would be Hegseth. But who knows if Blackburn will play ball.

Rubio's an especially likely choice, because being able to leave is his main advantage over Vance in running for the nomination. Vance is stuck to the end, but Rubio can resign and start to separate himself a little more than Vance can.

The main downside, though, is if he resigns before anything material happens in Cuba, it's going to really disappoint a very important constituency for his Presidential run. The midterms were already a massive shot in the arm for Meatball Ron, and we should certainly expect him to throw his hat in early. That's already bad news for Rubio, since DeSantis will suck up a lot of the resources (financial, political, and consultants) that are the lifeblood of the early stages of a Presidential campaign. If Rubio leaves without having delivered liberation to Cuba, even after Trump took such bold action in Venezuela, it's going to create difficulties for him.

But on the whole, leaving makes sense. Perhaps with a long lead time - say, March 31 - that allows Trump to get a replacement through the Senate but gives him enough time to maybe get one or two more things finished on his way out the door.