The name of the hook could be core\hook\course_category_delete, please note that the "pre_" prefix is not necessary any more because this type of hooks is always executed before the action.

Example of current usage is recycle bin.

In the future we could also add core\hook\course_category_is_deletable and core\hook\course_category_is_movable, {}these would be use useful for protection of tenant categories for example.