The bill of rights is a list of restrictions on the government i.e., laws the governments must follow.
There is the supremacy clause, but goodness knows where that would end up here. _Everything_ involving real money or power seems to make it to the supreme court these days, and who knows what the political landscape will look like by the time it does (yes, I am asserting that the supreme court has become more political than it used to be, _and_ that it used to be pretty political...).
Taken literally, yes. But legally, many (but not all) for the rights have been 'incorporated' to apply to the states. This includes First Amendment.
https://en.wikipedia.org/wiki/Incorporation_of_the_Bill_of_R...
The First Amendment as it is literally worded is, since it specifically says "Congress shall make no law...". But the rest of the amendments have no such restriction; they just say certain things shall not be done, period. Given the Supremacy Clause, that means those provisions should apply to all levels of government, not just federal. (Granted, the courts originally did not interpret them that way, but IMO they should have.)
That said, current jurisprudence, regardless of the literal wording of the bill of rights, is that they apply to the States, even the First Amendment. IIRC most Supreme Court decisions along these lines have cited the Fourteenth Amendment.
That hasn't been the case since the ratification of the 14th Amendment way back in 1868.
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
Courts have repeatedly held that the Bill of Rights does apply to the states, by means of this so-called "due process clause" in the 14th Amendment.
Edit: changed "incorporation clause" to "due process clause", as that seems to be the name under which it is more generally known.
Commercial Speech is a narrow carve-out for "advertisements and solicitations". It's not applicable to Twitter moderation.
The law does not make any requests about how Twitter should moderate things, it asks for information about how Twitter does moderate things. First amendment protection should ensure that government is prohibited to impose restrictions if a company says they will/won't ban accounts for praising Hitler, however, the people certainly have the right to take action in response to that, and the government has the right to compel Twitter to disclose to these people truthful information about their media product.
If they have a policy document stating "posts which contain more than three letters 'z' shall be deleted", they have a right to moderate this way if they wish - however, do they have a constitutional right to keep that policy document secret from the public? The way I see it, laws are permitted to regulate the disclosure of company policies.
If companies can now argue that complying with a law is against free speech, they can literally ignore all laws.