Undo options are user friendly! And what if you really actually want them to use your face data, but hit it by accident? Maybe it's best if they just ignore the request all together. That way you can both feel good about things, users think they got what they wanted, and Facebook actually gets what it wants. Everyone wins. Except the user, who loses.
At Amazon new products have a press release written during the spec phase (to help frame the pitch internally); I presume, at this point, fb writes an apology during spec phase...
Just so they can be sure not to re-add it later.
Yeah. That's it! And they're sticking with that story.