It seems there's something wonky with the relationships established with required owned elements, required context role, and role subclasses defined in DPUB ARIA.

ARIA 1.1 has a note in the Required own elements section that says:

An element with a subclass role of the 'required owned element' does not fulfill this requirement. For example, the list role requires ownership of an element using either the listitem or group role. Although the group role is the superclass of row, adding a owned element with a role of row will not fulfill the requirement that list must own a listitem or a group.

This means for instance that doc-biblioentry cannot be used as the unique children of a list, which invalidates Example 6:

<section role="doc-bibliography">
   <h1>Cited Works</h1>
   <div role="list">
      <p role="doc-biblioentry" id="b8cab5dd-bc24-459c-9858-7afa9da69b64">
         John Steinbeck, The Grapes of Wrath (New York: The Viking Press, 1939)
      </p>
   </div>
   …
</section>

In other words, doc-bibliography is only usable on li children of ol and ul.

Can we clarify that with the ARIA folks (cc @w3c/aria)? This looks like an oversight in how DPUB extends ARIA, or maybe even in ARIA's own extensibility.