I was able to accomplish this by looking at the Promoted State field on the site page. I use this to make a draft of a status report at the beginning of the week, then publish the report at the end of the week. Stakeholders are notified only at publishing, people that need to contribute to the status report are notified of the draft.
My trigger looks like this followed by a conditional that ignores the Templates folder and only continues if the Promoted State is greater than 1.
Trigger: When a file is created or modified (properties only)
Library Name: Site Pages
Folder: /SitePages
Condition: Folder path doesn't contain Templates & Promoted Status > 1
Power Automate screenshot showing how to determine when a news item in Sharepoint has published
The "Yes" path is when the content is published. The "No" path is when it is a draft or modified. YMWV on how to make the "No" path work right for your organization.