My point is that in the US, the narrower legal/constitutional concept of free speech is often implied, inadvertently or deliberately, when people are actually only referring to it in the broader sense that you describe. For example, a banned Twitter user might say things like "Twitter is a disgrace to democracy"[0] which confuses others into thinking there is some constitutional or legal harm being done when in fact there is none.
I have no problem with having a debate about whether the core concept of free speech is a universal right that should be guaranteed everywhere (surprise: I don't think it should be a universal right and I think it's downright dangerous to society to force all private entities to respect it). But I see the two meanings get confused so much that I felt a need to call it out.
[0] https://www.newsweek.com/donald-trump-news-twitter-marjorie-...