If the post can be re-dated to make it look recent, it's a small step to also shift the dates on the comments. This affects most review queues; IIRC only the Suggested Edits review queue doesn't show them.
The purpose of a review audit is to see if a user pays attention. You can make all sorts of changes to make it less obvious it is a review audit, but what does it actually matter? If you want to know it is a review audit, you can just simply click the question link and you will know for sure. A robo-reviewer won't do all that.
I am not against your feature request, I just think we could spent time better on something that helps the community more.