Judging from this post, it seems there are lots of regulatory holes in the way Automattic operates in the EU. Mullenweg needs to be careful that the eye of the EU doesn't turn its gaze towards him and his company, or he could be in some trouble. But I can't say I'm surprised by his belief that he only answers to US laws and jurisdiction.
The mention of the self-employed employees could be interesting to HRMC in the UK, if they are skirting around IR35 it could end up with them being handed a large tax bill.
Also their UK branch is called "MINISTRY OF AUTOMATTIC"... really.
I would argue that his recent behaviour warrants Automattic (and WordPress, as its dependence) being classed as a Designated Gatekeeper by the EU Commission under the Digital Markets Act.
