Mmmm the dictionary says it means "the right to express any opinions without censorship or restraint"

Again, you don't understand what that means. They are a private entity - "censorship" has no meaning there. You have exactly 0 rights on the twitter platform, as it's not a government entity.

There is a difference between "Freedom of Speech" the principle, and "Freedom of Speech" as defined in the 1st Amendment.

They are obviously referring to the principle in this case. But maybe you don't understand what that means.

That's not exactly true. The public has the right to have all laws applied fairly. The social media platforms have enjoyed the rights of a neutral forum without the liabilities that come with being a publisher. Yet the platforms act like a publisher, deciding what is seen or not seen, and the public directly or indirectly suffers as a result. This is a pretty clear case of actual rights being violated, despite the distracting narrative of "muh private company".

The tech companies have a clear liberal bias, despite what the media wants you to believe. Tech savvy people tend to be more liberal, and tend to spend more time on social media, so you have a bubble of opinions that drown out the other noise (which already gets downvoted to the bottom, shadowbanned, or censored anyway), resulting in the faux appearance of a consensus that there isn't a real problem here. Anyone with enough influence to have this opinion really noticed in the mainstream media, will be discounted as a "conspiracy theorist".