Yes. There's pretty extensive evidence that Mullenweg engaged in an extortion campaign against WP Engine, threatening to use his position at the WordPress Foundation to sabotage their business unless they agreed to pay Automattic a bunch of money.

Like many sociopaths, he prefers not to draw a clear distinction between actions he's performing for his own benefit and those he's performing on behalf of others, so he often tells a very different story about this. He claims to think, and may actually think, that there's nothing strange or alarming about the open source WordPress project taking sides in a commercial dispute between two vendors.

Indeed, I suspect if you sat down with him in private he'd explain to you that things like the Wordpress Foundation or fiduciary responsibility to Automattic shareholders are legal fictions. In his reality, he's the WordPress guy, and anything which seems to limit or constrain his control of WordPress is just some nonsense he signed off on to keep the suits happy.