What I came up with is that, they are showing us this becuase they won't get a chance to show this afterwards. As the child might be a girl, or something might happen to it before it takes birth, or last but not the least Laali might not be pregnant at all😆. So Loha will not get his Waaris, and by showing us these celebrations they r trying to prove how excited Loha is, so that they can justify his actions that he will take once he finds out that the Waaris is not coming.
Well this is what I think. They problem would want to create some drama before the waaris arrives becuase that will be climax to the plot that's running for almost 9 months now.
😆