include_browse=True does not mean that USE CATALOG + USE SCHEMA are enough to list registered models.

What actually happens is:

With only USE CATALOG and USE SCHEMA:
include_browse=False → 0 models
include_browse=True → 0 models
After granting BROWSE on the catalog:
include_browse=False → 0 models
include_browse=True → models are returned

So include_browse=True includes models that are visible through the Unity Catalog BROWSE privilege, even when the principal does not have EXECUTE on the registered model.

In other words, EXECUTE is still required for normal access to the model, while BROWSE allows discovery / limited metadata visibility.

That explains why the API can return model metadata without EXECUTE when include_browse=True.

I hope that helps 🙂