People are pointing out that there has been a pattern with what is on the mile 13 marker being the theme of next year's race.
In 2014, Mile Marker 13 was Anna & Else...Frozen was the theme for 2015.
In 2015, Mile Marker 13 was Ariel...The Little Mermaid was the theme for this year.
Mile Marker 13 this year was Snow White, so people are thinking that this (along with the 80th anniversary of the film being next year) points to her being the theme for 2017.