No, it's not true.

WPEngine used "WP", which until a few weeks ago was explicitly stated as "feel free to use". Nominative usage also says factual statements are protected. If you offer WordPress hosting, you are allowed to say "We offer WordPress hosting". You might highlight (and WPE did) that "WordPress is a trademark of...".

Matt's claim, "My mom is confused and thinks that WPEngine is part of the open source project", is a deflection, and laughable coming from the man who runs wordpress.org as a "independent website" (running on the Foundation's IP addresses) and wordpress.com as a for-profit business. That seems just a little more confusing.

> Open Source Contributions Mullenweg criticizes WP Engine for not contributing enough to the WordPress open-source project relative to their profits

WPE donated hundreds of thousands a year to events alone, maintains several of the most popular plugins (all of which are free to use, unlike several of Automattic's, which are commercial).

> Core Feature Modifications WP Engine is accused of altering core WordPress features, particularly disabling post revisions by default

This is laughable. It's literally a configuration option in the control panel. It just defaults to "disabled" on WPE.

> Mullenweg argues this compromises the integrity of WordPress and its promise to users

Why is it even a configuration option, then, Matt?