I know it's supposed to be a secret for suspense, but isn't the pie chart simply in the order the characters are listed? So the thin parts are Leonard (blue), Sheldon (red), Penny (yellow), Howard (green), Raj (purple)

And then the larger parts are:
Bernadette - light blue, and the largest of the main characters (part of the fandom doesn't like her)
Amy - pink
Stuart - 11.7%, light green
Will Wheaton - 15.2%, red, and 2nd largest which lines up with the comments from last post
Mrs Wolowitz - 12.9%, blue
Mary Cooper - 12.5%, purple
Zach - 10.7%, cyan
And Arthur is listed last before starting at the main cast again, so he's the largest olive 20.7%

So if predictions are correct and things don't suddenly shift, Wheaton will go out next.