Not necessarily. The First Amendment is implicated if the federal government is trying to get these companies to act on their behalf and censor speech.
Right, but this subpoena isn't doing that. The 'inadequate response' in the title of the post is referring to the companies' response to congress' request for data, not saying the companies' response to the speech on their platform was inadequate.
Yes, I understand that. My point is that many in Congress want these companies to preemptively censor what happens on their platforms and these subpoenas is an attempt to build that case.