This is what I think and purely my POV. We know how CVS sometimes incorporate few things that forum people talk about.. this could be one of those to show shagun in better light.
People complained that how shagun only cares about Pihu but nothing about Adi. This conversation is to point out how good shagun was for both Adi and Pihu and how she took care of them and stood by them.
Because no one has a clue about what happened in these 7 years in Bhallas house.
Adi being nice was also trying to make shagun happy about herself with his friend's staged comment to diver her attention from thinking negatively. because negative shagun is bad news for Ishra in the middle of Ruhi's custody.