I m not missing that part, because it hasn't happened yet. Imaginary injuries don't have evidentiary value, regardless of their potential possibility; thus it would be improper for a court to pronounce upon them - that's what legislators are for.

You're overlooking the fact that requiring Twitter to retroactively alter its own terms of service once it provided services to the government would be a violation of the takings clause. In your hypothetical example, it's more likely that a court would enjoin the government official from use of the company with the overly restrictive ToS for official business, rather than forcing the firm to alter its policy.