Hierarchical post types missing attributes meta box if post type doesn't support 'page-attributes' or have templates

[natereist]

Setting the hierarchical argument to true in the register post type function doesn't enable the post parent automatically. In order for this meta box to show up you must also enable post type support for page-attributes or the post type must have templates. I would think the post parent dropdown should be visible by default if the post type is hierarchical. This applies to both the Classic and Gutenberg editor.

[SirLouen]

This was sorted out in Gutenberg some time ago (I don't remember a Gutenberg without this).
For classic editor, given the current status, it doesnt seem to be convient to add new features as this has been for a couple years now.
Time to close this.