If so... meh?
Interesting response on reddit:
I'm not saying this is fake, I'm saying this is a placeholder for the actual release.
Ravnica. City of guilds. A plane whose main planet is covered in a large city, also referred to as Ravnica.
A setting where the city is the entire reason for going there. A place that isn't Faerun. A place where the inhabitants have an entirely different way of life than that in the Realms. A place where you could meet anybody, make any deal, where travelers from across the planes meet.
Does this sound familiar?
Ladies and gentlemen, you're looking at the placeholder for Sigil.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.
(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.