I wouldn't have wanted them to kill off the character. I would have accepted a recast or even something as drastic that she fell in love and moved to Europe. For a real life explanation it does make sense to say they are no longer friends, especially considering the real life circumstances. And it could be a subliminal FU to her from SJP. But for the fan, it doesn't make sense for the sitcom characters. That is why I mentioned the tv movie of Mary & Rhoda. The audience was told that these two best friends had a falling out that lasted 20 years. During TMTMS and Rhoda, Mary and Rhoda couldn't stay mad at each other for 48 hours, must less to not talk to each other, all those years, about marriages and births of daughters., just wasn't plausible for a fan of the show.