I can't agree.
The notion of 'accept' implies that an offer has been made.
No superstar would see the notion of a demotion being part of a career plan. They would most likely see themselves holding the position they achieve, but not rising out of it, if their career were to falter.
No superstar is going to foresee their status fading - these people are egoists who may accept that other superstars have 'fade potential' - but not them.
I agree with all of this except the opening sentence.
Sure, you can't accept an offer that hasn't been made. But the sentence is:
As the person's superstar status fades, he jumps ship, accepts a demotion, or takes a lateral transfer.
This could easily be, and, as I read it, probably is, a general description of the way these things happen, rather than an outline of what is happening in a particular case. When such a person's status fades he may find himself offered a demotion: as you say, a demotion is unacceptable to him, so he jumps ship - in my view, he goes to another job there's any question of this offer being made.
Can you see this as a interpretation, Max? I can't easily envisage an alternative.