It looks like ncsoft's attorney filed a trademark on Secrets of the Obscure in March using a shell company called Secret River Enterprises. It's the same attorney that did other GW2 trademarks. They also did not prefix the trademark with "GUILD WARS 2: " like the other expansions.
I feel like it can only be better than the other two releases. We will see :)
Why does people call it an expansion though? Didn’t ArenaNet themselves say that they won’t be calling it expansions anymore, but more like a “constant” stream of content?