Twitter saw speech they disagreed with, and they fixed it with more speech. They haven't censored any of Trump's arguments, they didn't delete his tweets. They just added their own commentary on top of them. That's what Republicans have always claimed they wanted. Argue that people are wrong, don't censor them. Don't throw people off the platform, add a fact-check.
I grew up listening to Republicans rail against the Fairness Doctrine, and I basically agreed with them on that point. Forcing private broadcasters to act like they were neutral on every issue was problematic. But now apparently that's flipped and free speech means forcing a private company not to take sides on any issue, even when taking a side doesn't require censoring or restricting anyone else's speech.
Any Republican that was genuinely anti-censorship would be cheering Twitter's move, even if they disagreed with the content of this particular fact-check.
So wave the bloody shirt, that's AOK, but say that vote by mail facilitates fraud, and you get a personalized "We Don't Think So!" message from twitter.
Twitter hosts outrage mobs that have the stated goals of getting people fired, and it has caused people I was following to quit the platform.
They simultaneously want to exercise editorial discresion while not being liable for for all the outrageous or outright wrong speech they do host.