Here is a possibility, in my opinion....
All of us are so used to the fact that an actor leaves soap by an accident, and another comes back by plastic surgery....May be Ekta is using this common knowledge to misguide us and bring a much needed twist. There was this speculation about Tulsi leaving the show, and that got viewers back. Then, a hoopla about who will come, and then people are wondering if Smiriti is simply on break, and if so, how she will come back....
What if Gautami (who will never accept the show for 3-4 weeks) is just a fraud that the doctor (possible Ram Kapoor) and Gautami are part of the plot. Tulsi/Smiriti may be very much alive, but the doctor may have learnt about Tulsi's life through treatment and hypnosis etc., so they are new villains that will play against all the old villains now...This way the story gets a new twist with all the publicity, and Gautami does not have to fit into Tulsi's shoes, and Tulsi can come back when she is ready.
Isn't it possible? Any thoughts?