One of the elements missing in the intra-US debate is that a lot of the hostility that much of the country feels toward Silicon Valley is generated from a very similar feeling. To many, how culturally distant elites on the coasts are from those in "middle America" coupled with how much power the former has over the later ... it can, at times, make it feel like there's an element of foreign rule. Technology has made it a lot easier to project cultural power - once you have it. Once you lose it, it seems it's almost impossible to get it back.
(Plus of course what will actually happen is that Facebook and Twitter will comply, and Indian users of those platforms will be subject to both the whims of California-based moderators and the Indian government's current penchant for objecting to pictures of funerals and suggestions they might not be doing a wonderful job. The potency of control of information and ideas in action; nobody in the upper echelons of the Indian government cares about Zuckerberg's policy on the lab-leak theory...)
If your country is consuming information through the filter of the American coastal elite, then they are likely to come to believe in the things that the American elite believes, to despise the things that the American elite despises. We can meaningfully speak of individuals having a choice to believe this or that, but as a society, that kind of domination of information will predictably drive people to believe what they are told to believe.
It cares not in the slightest whether Indians get access to things Facebook cares to censor (which they can anyway, through the large majority of Indian media Facebook does not influence or seek to influence) but is determined to browbeat Facebook into removing evidence that the Indian government's handling of COVID might be suboptimal. This is the purpose of the policy. Reinstating posts on lab leak theories is not the purpose of the policy, and the American coastal elite (or Bangalore tech elite) will continue to censor stuff they want to on their platforms in addition to the more pervasive and more universal Indian-government censorship.
Takes a remarkable degree of dishonesty to make freedom of thought arguments in favour of the Indian government being able to prevent any material it does not agree with from reaching Indian eyeballs.
The reason for the ban is obvious. Twitter tagged propaganda by the government as fake news.