Well, I think it would be very reasonable for a government to compel Twitter to allow access without an account to at least certain accounts that dispense information that is of real-time public interest. e.g. In the case of some recent wildfires here, updates about the emergency were primarily available on Twitter.

The sanest implementation would probably just be some nominal monthly charge that an account holder can pay to Twitter to have their account publicly accessible to all.

The coercion inherent in the Brasilian ban (massive fines for users who dare use VPN to access Twitter, massive fines for ISPs who don't comply) is many orders of magnitude greater than the coercion inherent in a paywall.

Accounts are free and easy to create, so it's your choice rather than a restriction on your rights.

You have a right to vote in your country, doesn't mean that you can demand they collect the vote in your bedroom and claim your rights are violated if they refuse.