This is totally my take of the whole twist, based on my belief that Anu is faking it to let go of Pre forever.
My guess is that when Anu happened to know the truth of Sonalika, he would have confronted her. And most probably Sonalika would have shown the video of Prerna pushing Viraj off the clip and put forward a deal with Anu regarding Prerna & Sneha. Remember how Sonalika had visited the accident site and while returning from the site after getting Mohini's call, she had 2phones in her hand. So, Anu who initially wouldn't have agreed to it would have sat & recollected all the past about them. His yesterday's words to Prerna was the reflection of what all he had recollected that day. Anu has seen with his own eyes and heard with his own ears how Prerna was fighting with Bajaj and warning him that she doesn't want to be important to anyone else than Anu. During memory loss track, Anu has seen several times how Prerna tend to be suicidal in the process of protecting him. Anu has also heard from Veena how he has always brought pain to Prerna. And above all, Anu has seen how his mother was insulting Prerna w.r.to Sneha's paternity. In short all these realizations would have forced him to take a decision to push Prerna away from him forever. Last time he saw how she came back even after being insulted publicly. Yesterday too she was not ready to believe that Anu betrayed her until she saw Anu getting initimate with Sonalika. So, just like how an affected area is removed in a cancer patient to protect the other parts, Anu decided to remove the cancer in Prerna’s life, i.e., him and that is why he had to take this extreme step of betrayal and not only that, he didn't want her to remember him in any way & hence decided to keep Sneha away from her. Remember how Veena recently was telling Anu how Prerna was emotional and reacts instantly without thinking. CVs just like that has not inserted this dialog there when we all already know this fact beforehand; it for sure has some significance in why Anu planned to betray her in such a cruel way. And the reason why he delayed the marriage by 2 days is to ensure Bajaj's arrival. So, Anu with Bajaj's help has planned to portray himself as a betrayer, while through Bajaj, he had made sure that Prerna was safe. And what all Bajaj told her and Prerna saw in the farmhouse after that was a deliberate attempt to keep her in the illusion that Anu betrayed her. Because Anu wanted her to hate him to the core, so that she will never return to him in this life. Anu knows that Prerna can be happy only in his presence. Buy he also realised that him being in her life means, she will never have peace of mind & will always be under threat. He realised that when Prerna was with Bajaj, she was not happy; but she was safe & sound and that she found happiness in Kuki. The reason why he himself brought back Bajaj in Prerna’s life.
By this logic, all the characters are back to their basic traits. Anu, the one who decided to be a thorn bird in the first go itself; Prerna, the impulsive girl who takes everything at its face value; Bajaj, the selfish person, who instead of helping Anu to get rid of SL/KL, decided to use this opportunity to get Prerna back in Kuki's life and Sonalika aka Komolika, the overconfident and tyrannic lady, who has always got everything she desired by hook or crook. And the upcoming track is the journey of how each of them changes with the unexpected happenings in their life and the after leap track will be how these changes help them in approaching problems in a different way.
Kyunki Saas Bhi Kabhi Bahu Thi 2
