Deleting a comment that somebody had already deleted failed, with an error naming a node that could not be found.
The two people most likely to see it were the two most likely to be working together. Open a document alongside a colleague, they delete a comment, and for a moment your page still shows its marker — the list refreshes a beat later. Click Delete in that beat and you were told the comment could not be removed because it had already been removed. A quick double-click of the delete button did the same thing.
Deleting something that is already gone is now simply done. The outcome you asked for — that comment, not there any more — is the outcome you get, with no error and nothing to dismiss. The marker disappears as the list catches up, exactly as it would have done anyway.
This is not a matter of hiding the message. Every other reason a delete can fail still says so, as plainly as before: something you are not allowed to remove, something another rule is protecting, something that did not finish. And a deletion that found nothing to remove still records that it removed nothing — so a clean-up that was expected to clear a whole folder, or a mistyped path, is still perfectly visible to anyone who goes looking.
The change is in the platform rather than in one screen, so it holds anywhere a delete can arrive a moment late: the comment you and a colleague both reached for, a page open in two tabs, a menu clicked twice, a script run a second time.