It states clearly that it's also "to allow us to operate Patreon, promote Patreon, ...". So if your content would make a good ad for Patreon, you've given them

It states clearly that it's also "to allow us to operate Patreon, promote Patreon, ...". So if your content would make a good ad for Patreon, you've given them permission to use it without compensating you.