Is there a possibility that Stan will get written off as well?

Maybe. If he doesn't leave, yay. If he does, we can't do a thing about it.

I don't think so. He is a main character, that would be like writing off Cartman. If they did that, well south park wouldnt be the same without stan.

I highly doubt it for the main reasons of :
1) If the death of Kyle is true, basically two of the main characters will be gone! Lets face it- south park will never be the same.
2) With Stans having his parent split && Move houses- There are so many different story lines they could make with this.
3) Who would replace them both??
Not to mention all the others i cant think of! (:

im not sure, from what i guess stan will move into kyle's old place after he dies and kyle's family moves away. and kyle has NO chance whatsoever because his death was confirmed by matt and trey. they could use kyle's official death as the crutch to bring back stan. kyle CAN'T come back, stan still has a chance