User blog comment:James12708/Why Exactly is Sheperd on Earth if Arrival Wasn't Completed/@comment-4973403-20121203023412/@comment-4950455-20121203031359

As discussed below, Arrival is "canon" in that the Alpha Relay and Bahak system are destroyed whether you actually played it or not. But whether Shepard was involved does depend on if you played it, and that's been the case ever since ME3 came out.