If you ban a massive centralized network, another one will take its place. It will certainly be smaller than Facebook, but no less centralized. And in this particular case, I would imagine that based on the Indian government's grievances with these American networks, information will almost certainly be less free on the replacement.
Email, Facebook, SMS, Twitter, and Discord are all massive networks that all can also facilitate small group conversations.
2. The total number of people talking on all networks will probably go down.
The decrease in 2 is probably orders of magnitude larger than the increase in 1. I don't think that it's necessarily a positive change.
Bigger companies have much bigger kitty and clout and they can fight back when something unreasonable is being pushed down the throat.
Smaller companies will be completely at the mercy of the governments.
I am guessing that these companies are deliberately waiting for a court case.