One can only imagine what this means. Why would an HR person need to 'thrive in ambiguity'?
For the same reason Government do. The more 'grey' or ambiguous the subject matter is, the less likely they can be pinned on something specific. They also like to use terminology like 'intent', again, that way they they eliminate specifics out of the equation and it is more difficult for those on 'the receiving end' to be pinned or made accountable.
HR are always a smoke and mirror outfit, whatever the organisation.