The document.page content for category is required as in 12.0 but in IHM in 12.0 we can create a category without fill this field.
It's only one fix to retrive the same behaviour but investigation in the field definition and computation will be great
* move menus to a higher level.
* fix categories search view.
* fix create menu action not being accessible in any way.
* reorder form view, focusing in the content, not in secondary fields.