Really? I think the text of the pop up is “new number found for CONTACT NAME. Add it to contact?”
That would be weird to me.
For a consumer platform, it makes some sense, and the prompt is supposed to be “hey you might want to do this”, and the user can decide if it makes sense. I’ve used an iphone since they came out, have seen this prompt like twice, and got it right both times. But I’m not a national security advisor or anything so maybe it’s more clear to me.