I get all of that. What palps was doing to the Jedi under their nose is well documented and understood. But if a group of Jedi are investigating an evil that is happening, and the said evil labels themselves as sith, then I would assume the Jedi council would dig deeper on whether they really are sith or just a bunch dark user types not affiliated with the sith or rule of 2. Papls was pretty damn good at being incognito with his sith ways towards the Jedi and the Jedi being full of themselves was recipe for disaster. The Jedi needed to look inward to find the root problem. This is out in the open compared to what Sideous was doing. If this evil turns out to be operating like the inquisitors were under Sideous/Vader then it’s going to make what transpired on the council in the prequels more complex, especially Yoda being alive for all of it.
After I made my initial post, I did see Jodie Turner-Smith is playing “Mother Aniseya”, a leader of witches. So that could be the dark side of things we’re dealing with a la nightsisters.