Pradeep Srikakolapu says good riddance:
In our earlier announcement, we shared that newly created data warehouses, lakehouses and other items in Microsoft Fabric would no longer automatically generate default semantic models. This change allows customers to have more control over their modeling experience and to explicitly choose when and how to create semantic models.
Starting November 20, 2025, Power BI *default* semantic models are disconnected from their item and become independent semantic models.
Click through for an overview of those changes and how you can get rid of the default models you may still have hanging around.