> previous poster interpreted "buy a considerable stake in these American social media companies" as give Elon Musk money.

Which social-media companies did you mean? If Twitter is among them, then that is, at least indirectly, giving Musk money; and, if not, then it's hard to see how buying that stake would help to ensure communications reliability, since Twitter seems to be much more common than any other American social-media company as an organ of government communication.