They used to, until the WP Engine fight began. The trademark policy was updated a few days after Matt started publicly beefing with them. There’s now the following on the trademark policy page: https://wordpressfoundation.org/trademark-policy/

  The abbreviation “WP” is not covered by the WordPress trademarks, but please don’t use it in a way that confuses people. For example, many people think WP Engine is “WordPress Engine” and officially associated with WordPress, which it’s not. They have never once even donated to the WordPress Foundation, despite making billions of revenue on top of WordPress.