Not really. That "arc of history" line is just propaganda. Twitter did play a roll in these changes. Whether these were towards "justice" or not depends on your viewpoint, of course.

The people end up on top see the outcome as just

Winner write history

So whatever happens, it'll be called just...until it isnt

To make an example of my point, how could the American Revolution start in 1765 without Twitter? Something else did play a roll and was good enough. That revolution even succeeded.

Thousands of other data points scattered all along human history, successful or not.

It gets more and more difficult to find "something elses" as each of them gets blocked or censored.

Everybody is born with a mouth. It's all we had for so much of our history. Add ink. Those were enough for all the movements that shaped the ancient and modern world.

When have you last physically given someone something written?