What other theories are there about the plot?
In April 2019, Murphy announced via social media that Season 9 was titled American Horror Story: 1984. At that point, we already had a vague idea of what the series was about: the teaser trailer featured a woman dressed in a very '80s ensemble frantically running through the woods from a creepy, knife-wielding man. This, plus the series title, made it pretty clear that 1984 was going to be an homage to the slasher horror that ruled the decade, drawing influences from films like Friday the 13th and A Nightmare on Elm Street.
Of course, each season of AHS has several subplots, which we can only speculate about at this point. But despite the lack of concrete details, fans have wasted no time theorizing about where things might be headed. Murphy is known for hiding clues about the next season in the one currently airing, and as many eagled-eyed viewers noticed, Apocalypse had a lot of references to space travel and aliens. The Carpenters' "Calling Occupants of Interplanetary Craft" was heavily featured in the season, as were multiple references to Russia. These clues could point towards a take on the Space Race, which seems possible if the season is set in the '80s.
While many fans were hoping for a continuation of Apocalypse with Season 9, that doesn't appear to be happening. Don't fret, though, because we do know that popular Coven characters will be back eventually, just not this time around.
Something else of note is the years-long theory that every season of American Horror Story represents a circle of Hell from Dante Alighieri's Inferno. Murphy acknowledged it, posting the theory on Instagram and captioning it, "Interesting."