Chill. Even if the leak is true Vodaynitsa is not replacing Signora. That's not what the leak says.

The leak claims that she takes her JOB not her TITLE. This means that Vodaynitsa is the new emisary and negotiatior of Sneznaya. Which would make sense, they someone doing that.

Also, In all the merch they have sold Rosalyne=La Signora. Vodaynitsa becoming Signora would be confusing.