Why do you think it's not both?

>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.

Referential use doesn't allow someone to use marks to imply an association or endorsement, and I think it's clear what they're calling out in the trademark policy changes.