There is no specific trigger action for whenever SharePoint news is posted. This article explains how you could work around this by using a trigger condition expression.
Sometimes using tags in Teams can be useful. However, there is not a specific trigger action for this. This blog shows how you could use a trigger condition for this.
In this article I am going to demonstrate how you can create a draft SharePoint page with an embed web part in SharePoint Online via a Power Automate flow.