If WP Engine is reading, fork WordPress now. Call it FreshPress. Put $25M into it, team up with other hosts, abandon the editor everyone hates, and relicense it to GPLv3 so Matt can’t have any of it. (Note that WordPress’s license specifically says GPLv2 or later.) Maybe support Composer like sane modern PHP projects. Maybe put the most important plugins like Woo into core and make it an all-in-one Squarespace competitor.
Once it’s ahead, legal, and Matt can’t borrow; then he’ll realize his bluff has been called. Make WordPress the new B2.