[1] - https://www.bbc.co.uk/programmes/p035w97h/episodes/downloads
For me, free speech is fundamentally about trying to rectify the injustice of an imbalance of power between those in authority and the ordinary citizen. During the Enlightenment, the authorities were monarchs, but even before that, the origins of free speech can be seen in the Reformation, the authorities being the established Church and the battles being eg the right to a Bible in your own language or the right to worship without priests.
In modern times, authorities can be just straightforward, well, authoritarian. Global leaders & business people who tweet or post on FB carry an authority ex officio that make their proclamations much more acceptable to the neutral reader. That in itself is a dangerous situation and Twitter or FB absolutely need to take control. If these companies want us to take them seriously as champions of free speech, they have to play their role to help restore that balance of power, by being far more stringent about fact-checking the tweets of those global leaders than they would be for ordinary posters.
Those right-wingers who love to proclaim themselves champions of free speech are really objecting to the Tyranny of the Majority. That is not an authority that requires a rebalance of power. It is just an established opinion.