Definitely there is a reason to bring back Vivaan after shown him as dead.
They can bring back KN or RV.
But they go with Vivaan.
That is why i feel it's about trust factor because Sukor not going to believe KN or RV but definitely Vivaan.
And don't know there is any connection with all these and Imli trying to ruin Chakor's brain.
It might look far fetched but still Chakor forgets about present life and about good Sooraj and Saanvi.
And Imli and Vivaan joined together and act as couple again and Chakor remember that time she considers Sooraj as her enemy.
And thinking KN is in jail and recreating that scenario again.
But this time both Vivaan and Imli acting and negative.
This is most unlikely to happen but there is lot of scope for emotional drama between Sukor and imagine if she forgets about Saanvi and all.