No, it is not. It explicitly is not. Freedom of speech is one right among many other unstated rights held in common by the people. The first amendment merely prohibits Congress from passing a law that restricts it. The wording is clear that this freedom is something that exists inherently beyond the scope of the Constitution, and is certainly not "provided" by the document. We naturally have rights such as freedom of speech. It is from institutions like the government that restrictions are placed on them.
Also, the 9th amendment was included precisely to clarify and codify the fact that the Constitution, in enumerating the rights, is not itself granting those rights or even stating that these are the only rights people have.
So, no, not so much.
Much later, actually; while the Supreme Court grounded incorporation in the Due Process clause of the 14th Amendment, which was part of Reconstruction, the doctrine of incorporation was articulated and developed in the 20th Century, starting, IIRC, with Gitlow v. New York in 1925.
Yes, it is. The idea of the authors (and those ratifying the amendment) that a moral right to freedom of speech exists independently may be (all or part of) the reason the Constitution expressly provides and protects the legal right to freedom of speech, by the legal right is provided by the Constitution.
- Just like users demand feature requests, people who are being deplatformed and people who argue against deplatforming are asking to support a feature called "free speech" and "open communication".
- Violation of contract. Users invest in growing the network and influence in these platforms with understanding that "free speech" and "open communication" will be respected. But overtime, the Valley oligarchs like FB, Twitter, Reddit etc pulled a fast one on their users coming up with draconian rules that wasn't originally part of the platform.