Taken in context "the truth" in quotes is alluding to the large number of people in the US who genuinely believe that the election was stolen, not the commenter's personal stance.
I put it in quotes because I observed people on both sides of the issue being convinced of "their" truths.
To me, the issue of how to effectively reach a general consensus in these matters is even more important than who is right or wrong. It is my personal opinion that this can only be achieved through transparency and openness, but, as always, I am my own harshest critic, so I entertain that I might be wrong.
I think they were implying that when people advocate for censorship, they seem to be the ones that have a very secure concept on "the truth," when in reality there is no such thing.
For example, there HAS been voter fraud uncovered this election, because there is voter fraud EVERY election. The question is one of magnitude. Has the Trump administration been able to provide evidence sufficient to actually change the result of the election? No. Most conservative pundits I have seen are extremely clear about this distinction. But is this going to ban them discussing it, or discussing new evidence that is being brought forward?
As other users have mentioned, this country went through 3 years of hearing about Russian collusion during an investigation that ultimately provided no evidence of that having been an issue capable of unseating the president or delegitimizing that election. Throughout that period, I didn't hear any arguments saying that discussion of that topic should have been censored, and that is a good thing.