There might be the possibility that it isn't something life threatening, just career threatening. That would mean she wouldn't be able to travel between London, New York, LA and where ever else she's been. It might put an end to her acting, not her life.
The thing that gets me is that they let this plot leak. Which usually tends to indicate that it has been leaked to a) boost ratings so people will tune in to see the fate of one of the most loved characters on the show b) someone inside is leaking information without the company knowing.
I mean the whole stuff with the fight between Brenda and Kelly, that is obviously a ploy to boost ratings now that Shannen has agreed to two more episodes.
*hugs*
xoxoxo