There's a reason KP is being brought in as Bajaj, firstly because his stint as Raman is still fresh in viewer's mind and secondly he will probably (I'm not sure) dedicate more time and atleast show interest in his character that can reflect onscreen too.
Bajaj is definitely one of the main characters of the show, nobody will deny it, but when the major Bajaj track failed even after huge buzz behind Swiss track and all the hype related to both ksg return and also the entry of an iconic character, expectations rose and were never met. We all remember how kasauti 2 even though had silly storyline was in top 5 always before the first Bajaj track started.
The show never picked up because later on the writers never gave the lead pair an opportunity to grow as characters, all they did us play ping pong with sacrifices, that's not how audience like to see the main characters of the show. The show did not need glorification of psycho komolika this long to kill off the viewers interest, the first season had komolika's presentation in a very subtle and bitchy manner who always used to give the center point of the storyline to AnuPre. This season they messed up badly, they still can rectify the mistakes in writing though.
This could be a fresh start for the show, writers just need to get one fact straight that to glorify other characters don't butcher the main leads. And yes just like previous season in this season also AnuPre can only love each other no matter even if they don't end up together, maybe they'll die together. Audience can atleast be very sure about the climax of the show 😝😆