I believe he also interacts (at least reads) almost all the comments made to him by his fans (which I am sure is a lot). It is a way in which an actor can keep his ears to the ground.
Especially how TV functions in India, it is needed for an actor to know what is working and what is not.
It is typical in theatre to take what we call "additions". When an actor faces a situation which is unexpected (like missing prop or another actor forgetting the lines), it is common for them to change the dialogue a bit to adjust the situation.
Some theatre actors do it to get laughs or add a punch line to get claps. In theatre, the reactions are instant and they tell an actor if the additions taken by him/her are working.
It is said that every rehearsal and every show is a drama in itself so these are pretty common. It is not an unusual thing to do in films too.
I am not really sure how much of the serial scripts are fluid and how much changes an actor (with enough experience to call a few shots) can bring. But it does seem that a few "additions" in terms of dialogues or designs ARE being done.
And they are adding interesting touches to the show! So bring it on!