This episode gives the writers a chance to explore what occurs should the team be unsuccessful in defending against Michael and his created race. The writers don't go into any details on Michael's success or failure, but we learn what might have been for many characters. We also discover Atlantis stands for at least 26 more years (with humans) and 48-49,000 years.
It was nice to have an (very brief) opportunity to see how the future might turn out should failure occur. Yet, we know (or hope we know) the Atlantis team will be successful and hence an alternative reality story.
A big thank you to the writers and producers and now, please, let us have the canon success stories.
Oh, one item they failed to mention . . . What happened to Dr. Beckett? After all last we saw he was using the same chamber as Sheppard.