User blog comment:Foreseer44/Confirmed: There Will Be 36 Contestants In The Ridonculous Race/@comment-2212492-20150221064314/@comment-25597478-20150222182944

I am pretty sure they confirmed no All Stars would be returning, but IDK

and probably not any PI characters, since I think they were starting to work on this before PI was even released

But Idk, that's just me