How? What specifically opens them up to litigation? It is a private company. It can do anything it wants as long as it is within the bounds of law. They have every right to ban anyone. Even on flimsy grounds. The idea here is to expose all the moral wrongs and bring it to the fore. Not that they are legally in the wrong (most cases they aren't). An audit is a good place to start.
Section 230, in brief, only provides immunity for social media providers from being responsible for the content that is posted by users on their platform. It has nothing to do with internal company policies. Rather, Section 230 actually enables internet companies to moderate content through the Good Samaritan protection.
So, it is actually worse that Twitter was moderating content in majority countries (except USA) where Section 230 wasn't even recognized. Revealing what exactly happened behind the scenes would not be a sufficient reason for litigation.
When Twitter was pulled up in India for its opaque moderation policies, it tried to quote American laws for its defense. In fact, when Jan 6th happened in USA, Twitter was quick to ban accounts of those who took part in the protests. 70,000 accounts were purged from Twitter. However, Twitter refused to ban accounts of those Khalistani terrorists who vandalized the Red Fort on Jan 26th in India and only partially complied with Government of India's orders. This double standard was visible to majority of Indians. So it is not like Twitter actually follows the laws set by the Country it is operating in either. There are multiple instances where Twitter has refused to follow directions by Government of India or by the Courts in India. You can read more about it here: https://www.hindustantimes.com/india-news/have-to-follow-ind...
So yes, moderation policies cannot be opaque. It has to be transparent. The reason for transparency is so that we know exactly why and for what reason was an account banned/shadow banned. If the Government of India sends a legal request for take down of accounts, it has to be complied with. Twitter cannot decide to invoke US laws in India.
Also, read this to understand more about this issue: https://techcrunch.com/2021/08/10/twitter-now-in-compliance-...
