Hmm.. That makes me wonder. Do "free speech" rights apply when it's not your speech? I mean, Twitter is not an editor, whatever it publishes is not its speech, it's someone else's.
The act of choosing to use (or not use) ones resources to relay speech is, yes, an act of free speech (or perhaps more precisely free press, though the two are generally treated as a single right under the name “speech” for most purpose).
> Twitter is not an editor
It is, except for some civil liability purposes because of the specific Section 230 carveout for curated/moderated content which is user generated, a publisher. The choice to publish content, or not, is a speech/press act.
It would be, except for Section 230’s explicitly carveout of most civil liability as a publisher for online publishers (whether other users or platform operators) to the extent they are moderating/curating user-generated content, rather than producing/submitting content.
Nope, publishers often (sometimes with explicit notice to avoid doubt) publish things they disagree with because they think there is value in publishing it. They often also exercise their free speech/press rights to not publish other things they disagree with, even if they are submitted to them for publication.