Describe your concern

This requirement

If a CSS selector includes a WAI-ARIA attribute (e.g.,
input[aria-invalid="true"]
), user agents MUST update the visual display of any elements matching (or no longer matching) the selector any time the attribute is added/changed/removed in the DOM.

duplicates an existing requirement. We should not duplicate requirements like that as it will lead to people being confused. If ARIA has to call it out, why doesn't SVG have to call it out or MathML? Does that mean an invalid attribute cannot be matched?

We should only require things once, even across specifications.

Link to the version of the specification or documentation you were looking at at.

Link to documentation: https://w3c.github.io/aria/#ua_noninterference and https://w3c.github.io/aria/#document-handling_css-selectors

Does the issue exists in the editors draft (the editors draft is the most recent draft of the specification)?

Yes.