LOL, so Matt says that if you use a plugin to change update settings (e.g. repos) and such, he considers this as a "fork" of WordPress.
Matt Mullenweg: WP Engine is using a fork of WordPress since they change settings.
You keep using that word, I do not think it means what you think it means
Matt is delusional, using a plugin does not make WordPress a fork. Considering how much features Matt butchers on WordPress dot Com unless you pay for the expensive business plan, should that be called a fork and be named something else?
Under his definition, it should.