Ford claims it doesn't cause any issues, but the rattling sound is clearly two or more metal parts flapping against each other, which any one mechanically inclined will tell you over time it will wear. But maybe Ford thinks it will last long enough for most warranties to expire, and then it will become an issue.
My problem is the shear principal of it. When I drop my kids off at school and pull away in a vehicle this new and expensive, I don't want the school principal hearing the sound and acting like something is wrong with my car. My feeling is this, unless I modify something, like an exhaust, I expect my cars to look and sound, well, you know, like their price. I know, a lot to ask.
I haven't heard back from my dealer yet about the techline inquiry. So I'll end up calling them back today or tomorrow. But also, 9 days, my god. I sure hope you had a loaner or something, or maybe you don't need one but that's BRUTAL.