I sent another email to AMC Theaters making sure that there wasn’t anything else bad in the popcorn (high fructose corn syrup, MSG), and I got this reply
Gil,
The nutritional information for most of our items can be found at their respective manufacturers’ websites. Our hot dogs are Oscar Mayer, our tortilla chips are Tostitos, our cheese is FunNacho, and all of our candy is name-brand.
Our popcorn is Orville Redenbacher brand popcorn seed. It is popped in a mixture of 100% coconut oil and butteral (a salt & butter blend which contains milk and soy). There are no additional ingredients in our popcorn besides what I have mentioned here.
Please let me know if I can be of any more assistance!
While milk and soy are debated non-paleo ingredients, for a fun time at the movies, this seems like very good news.

I just checked out the oscar mayer hot dogs they say they use. They all have CORN SYRUP in them!