You're definately overthinking it. Also I don't think the alt right would want to align themselves with a child eating killer clown....on second thoughts.
I use the "okay" sign all the time. It was a funny thing since I was a child. It's not like it's a sign some alt-right shit heads invented. Stop making it a "alt-right" only thing.
I mean, IT is essentially about the evil that hides underneath the surface of small town America so it could be intentional. There's many bits in the book that involve racists, homophobes, white supremacists, etc.