It’s irrelevant where it is said so long as it is said publicly.
Edit: This is the same reason Elon is now being sued for "Twibel". You cannot say state lies publicly without legal repercussions. "Funding secured" is classified as material non-public information.
I used to work in finance and regulatory compliance.
There’s no requirement that he lie that way in a regulatory filing, previous posters are trying to explain to you that it’s enough to make the claim publically. Lying in a filing would be a different crime.
Either the Twitter account is a financial venue covered by the regulations at issue, or making the announcement there was illegal independent of its truth.