Do people in Eberron generally know about the “13” thing or is it more meta?

do people in eberron generally know about the “13” thing or is it more meta?

Thanks for your time, excited for exploring eberron! People know about planes, moons, and marks, and there's many common superstitions that link these together. So there's a general sense that 13-1 is a significant thing.

— Keith Baker (@HellcowKeith) July 18, 2020