Twitter isn’t going to broadcast or link to tweets that were bad enough to merit a ban, for obvious reasons- they’re banning it precisely to avoid having that content be propagated any further.
From an outside observer, there is no way to distinguish between the claim that the ban is for "good reasons", or that the ban is a result of bias on the part of the company.
Perhaps this is fine in situations where the banned entity is a malicious actor, but it presumes a zero false-positive rate. My opinion is, if even one person is wrongly punished without recourse (other than rolling the dice with social media) then the whole system is unjust and should be reworked.
Why do you assume that it is integral to modern open communication? (hint: it's not, for plain reason that twitter does what's best for twitter)
For example, when it comes to publicly-available services such as this, we often hear about people referring to "Twitter's freedom of speech" in terms of censorship of its users, which boggles my mind. Twitter provides a publicly-accessible service that allows users to post short entries, and when they prevent someone else from posting something, it basically amounts to "Twitter's right to free speech is more important than the user's ability to speak" and that seems a bit counter-intuitive.
If Twitter's policies are unjust, then Twitter does not deserve the level of influence that it has. My opinion is that such a service could not have been foreseen by the writers of the Constitution. In their day, the greatest threat to freedom of speech was the government. Remember, they had just fought for their independence from England. I don't think they could have envisioned a world where the greatest threat to free speech would come from the private sector.
And if we're not careful, we're about to be making it worse. As it stands, platform operators are not generally liable for the things they automatically publish on behalf of their users, outside of certain highly egregious things (such as child abuse imagery), and even then only if they don't follow the proper procedure with regards to reporting to law enforcement, etc. If that ever changes, expect freedom of speech to be null and void in context of the Internet.
What transparency would you find acceptable? Do you hold other companies to that level? I dont know the books for my local grocery store, I dont know their justifications or reasonings for what they do or dont stock, when they decide to hire, or what rules they hire for.
I'm not trying to be antagonistic or dismissive - I am far from an "anything goes" libertarian (or a libertarian of any kind) but if rules about rules are arbitrary, then we're just doing what we complain about.