A common trope with Urban Fantasy stories. Advent & Union City have only the weakest of masquerades which is crumbling slowly but surly. After the Zero Point Event, the supernatural became far more overt after centuries of trying to hide themselves from mortals. Still, most supernaturals do not wish to reveal themselves to the public for fear of retribution. Vampires and werewolves obviously won't be lauded as new neighbors, they'll be the victims of a lynch mob. Wizards still fear witch hunts and stalkers. Bad things happen when just anyone can look you up in the Yellow Pages.

There isn't an enforced mechanic requiring a masquerade but most hide their “otherness” for fear of consequences. Who knows what would show up if you hung up a sign advertising your supernatural abilities?