What are some useful keyboard shortcuts? is a community wiki question.
The OP has commented below:
and their name is highlighted. It shouldn't be - they're not the poster any more, it's a collaborative question.
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I think the highlighting should remain.
Why? Because the OP of the question or answer is still the user that is notified on comments. It is still the one that is capable of performing some actions that are exclusive for the OP of a post. And besides that, it gives some context on the discussion going on in the comments.
So in short: The highlighting is useful.