>This post is showing that he originally supported the idea.

Yes ... and?

That still wouldn't make it legal. The lawsuit will be decided based on jurisprudence, not based on "what Elon thinks is right".

This is a very amateurish move, tbh. Did they hire Matt Mullenweg's legal team?

A useless argument. If Elon does, in fact, have the legal authority to prevent OpenAI being for profit due to his initial investment (and these emails seem to indicate that the other founders think he does), then it doesn't matter if he wanted it then, only if he wants it now when the decision is being made. The fact that this is being presented to the public and not to the court is further evidence of its weakness.