The season debuts on Wednesday night. They aren't revealing much about the first episode. http://southpark.cc.com/clips/f46apb/who-are-you-voting-for
Gotcha. That happens all the time in South Park. Trey and Matt do all the voices save for a few characters, and it's pretty easy to tell who does what. PC Principal, for example, sounds quite a bit like Randy, and in certain spots the voices are indistinguishable.
Episode 2 tonight. "Skank Hunt" http://southpark.cc.com/blog/2016/09/19/episode-2002-skank-hunt-press-release