Doc type editor does not set "resource-required" validator when a resource field is marked required

There is a special validator for required resource fields (in the document editor) at /hippo:configuration/hippo:frontend/cms/cms-validators/resource-required.

However, when marking a resource field in the document type editor as "required", it gets hipposysedit:validators=required configured, instead of resource-required, in its definition in the nodetype section.