This show is not about Kunal and Mauli. Show is about Kunal , Nandini and Mauli. That's what is was. Mauli did not have a POV in the promo. She was not important enough for the makers.
In pre-leap Nandini ke scenes were almost double of Mauli. Again she was not given importance. Drashti was anyway way more popular than Aditi.Its just that the EMA was so badly executed that KuNan was bashed and sympathies went with Mauli. People were not interested in KuNan anymore and it was about Mauli. That's when the first promo with Mauli POV was aired with the timeslot change.
That's when she actually became the lead and also Aditi s performance took everyone by surprise.
If Drashti had not quit , it would still be Kunal /Nandini and Mauli at the other end.
It did not matter even if Nandini was an insecure wife, she would still get as much screenspace as Kunal.So this was never a MauNal show.Insecure wife does not mean Kunal would fall in love with Mauli again. Many second wifes in Real Life are insecure.
Gajra had to change the storyline twice.
1. Due to sympathies with Mauli , she became the lead.
2. Drashti quit the show.