The [RR] 'resignation' is simply part of the same trap as Trump being baited into firing him after last week's leaks.
Those who Trump threatens will, in short order, simply say that [RR] was forced to resign. That is the same as Trump firing him (for their purposes).
If you cannot manipulate POTUS to cross the RED LINE then you move the RED LINE.
Remember, accepting someone's resignation is not necessarily the same as being fired. That is the game. If Trump 'accepts' the resignation then it will be reported that Trump fired him (Trump has crossed our RED LINE).