Well, how about litigation?
Paging Max Schrems, or someone else who can and will file such a lawsuit. Since WP does business in the EU, they either need to comply with the law there or cease doing business there, as far as I understand the GDPR. And since they've been ignoring the GDPR and doing business in the EU, they are subject to some serious fines, right?
A lawsuit of this sort would be, I think, a good thing, as the law needs to be tested in court and clarified as to how it will work in the real world.