At this point, It is very hard to say anything a lot of things are in development
First of all, I want to say that 8 months is a significant time. We viewers are unable to relate to it as it is just one day for us.
I am sure the leap backstory is saved for the episode when Viaan realises that Katha is engaged to someone else and then comes to her to get his answers.
I saw some reluctance between Katha and Yuvraaj. Yuvraj got the news of Sagai from third person, don't know who. 8 months time period is significant so, if there was some anger, it might have subsided by now. I suspect some relation between Grewals and this psychiatrist. Another way to look at this is that Katha has cutoff Grewals as she didn't seek their approval this time.
Don't want to say much about Aarav as I am unable to understand him even a little bit. Let's see what backstory they have for him.
I won't bash Katha for now as I have seen some things in today's episode which I am not sure of if it is true or not. Only, after further development, it will make sense. Also, 8 months is a significant time. Although Aarav is kind of annoying now. I felt weird when Katha was looking for a chance to see her engagement pictures with Viaan as if Aarav is her husband or Father.