I would say that the way things have been set up, the Witches of Dathomir could/should be a contender for villains that tie together all 3 projected movies projects (Dawn of the Jedi, Filoni, and Rey).
However, with the viewership of Ahsoka being as weak as it is, I am not so sure many would know what was going on.
The story has been decent as a set up. The visuals are stunning and the lightsaber duels have been mesmerizing. The dialogue and scripting, on the other hand, are absolutely PAINFULLY DREADFUL and exhibit why AI should never be used for scripting.