This pull request introduced the following statement into ARIA 1.3:

User Agents MUST NOT expose an ARIA attribute to the platform accessibilty API when the element's computed role prohibits use of the attribute.

Given something like <div tabindex="0" aria-label="foo">bar</div>, in which aria-label is prohibited (generic role), that means we need implementors to NOT expose "foo". We will not get vendor buy-in for this. Trust me. Yes, it's lousy authoring which is not ARIA compliant. But given the explicit author-provided label, user agents aren't going to ignore it in favor of "bar" or worse, nothing.

I think we need to modify the above statement to allow for User Agents to expose "foo" as part of handling author errors.