Not a mistrial if the jury is ignorant of it. I don’t know one way or the other what the jury is aware of, just saying ...
Not necesssarily a mistrial if they DO know about it. Either side can move for mistrial, and judge decides.
They go home at night. You can absolutely bet that the jurors have heard of threats to themselves and the judge by now.
And if they have less than total confidence in the Government assurances, they may be concerned that their names and addresses will be made public if they vote for acquittal.
Some of them might get angry and vote for acquittal simply in defiance of the threats. I would expect others to cave with the result of a hung jury.