Let's put this to rest. I felt like this tidbit given by Ryan was important enough to warrant a reworking of all our theories.
"A new Supreme will be chosen Coven’s Jan. 29 finale, which reveals Fiona’s (Jessica Lange) successor, will unfold a tad differently from previous AHS conclusions. ”It usually is a very nihilistic ending. But this year is different because it’s an incredibly dark-comedy ending, which I like,” says Murphy, who teases, ”Nobody has guessed who the Supreme is.”
-- ”Nobody has guessed who the Supreme is.” --
He's obviously referring to Zoe. Every single review site, fan site, and social media outlet has marked heras the next supreme and this was Ryan's answer to those assertions.