Personal free speech and assembly?

Tesla Says It Has Turned Over Documents to the Justice Department

Elon can try 'Citizen's United', claiming he himself cannot be robbed from free speech on Twitter.  

His board can fire him, or if he owns the board he can be Elon.  

But no. When Tesla incorporated was there any voluntary agreement to a blanket non-disclosure?  If Elon is blocked via some ex ante corporate disclosure agreement then Citizen's United is dead law.  Citizen's United invalidated that portion of the corporate agreement.  Conflict, this is why we have corporations, so government and agents can volunteer.

Citizen's United fouled things up.  In fact the corporate agreement is a voluntary contract between agents and the government agency.  Both parties can agree to a nearly blanket non-disclosure, it is contract law, we can voluntary (with the SEC and other government agencies)  give up some rights if it is time limited and not cruel or unusual.  In this case, Elon, like Citizen's United, are incorporated and have agreed to blanket speech control by the SEC and some government agencies.

What about the mayor spending his own time referendum affecting the union?  The mayor cannot agree to voluntary non-disclosure while being elected in a fair vote.  It is a violation of right to assembly for legislatures to specifically restrict the right.    But Tesla and Citizen;s United have extensive non-disclosures, the effect is to pre-qualify their accounting as business related, unaffected by external antics.