What I think is that, Aneeta ma'am or Channel V favours Shakti. I even have various examples. You have seen numerous of Kriya and Rey's promos while there are ONLY some of Swaron's. Also, in the serial, you can see that no. of times.See, Shakti has a huge fan base due to which The Channel might think that they will see a rise in TRPs if they show more of Shakti. That's what I think. There can be no other reason of Taani's removal.
Palki ma'am removal might be because of some internal conflicts. Maybe because they wanted Shakti to be there, and Palki ma'am may not be in favour of it.
Maybe I'm wrong, but as far as I can see, this is a plausible reason. Justified? No.
All i wish is that this gets over fast and you all, Swaron fans be able to see more of them.