Sounds like this is an automated approach to polling. There is a similar feature request for n8n on which you might want to leave a vote:
For the time being, you could implement a full blown polling logic like @harshil1712 has described here: Creating triggers for n8n workflows using polling ⏲ – n8n Blog (this is not specific to WordPress, but you can easily transfer the basic idea).
For something like “process new blog posts” you could alternatively just have your n8n workflow run every hour and then fetch any posts created in the last hour. Here is an example flow fetching all posts on the n8n blog created in the last hour:
Example Workflow
Of course, it doesn’t have to happen every hour, you can adjust the polling time as needed.