It's obviously not just a regular commit and everyone involved would know that. The commit log is not a proper place for a thinly veiled ethics complaint.
If you think something is wrong, have the courage to say so directly, don't hide behind a commit message.
As both employee and employer, it's my view that all employees should what they see as the right thing by default.
Personally, I think the poster should make the change and then announce it. I'm not saying he should be cowardly. If anything, I think the cowardly choice is to futz around trying to get consensus an elusive around doing the responsible thing.
Since they claim they won't use it and he says it was probably a mistake, this sounds to me like exactly the correct response: Let them save face and "agree" with the change if they are so inclined. A high handed accusation of an ethics issue does not look supportable at this time. And it is likely the worst thing he could do.
If you think something is wrong, have the courage to say so directly, don't hide behind a commit message.