This is the last time that you'll ever lose someone
after this it's you and your friends
it's you and your friends.
—Stars, "The Last Song Ever Written"
I have a theory about the end of Mass Effect 3.
Not a serious theory, mind you. A crazy theory, the kind even I don't take seriously, but find it fun to think about. Essentially, it's that everything in the Citadel DLC is not preceding the final events of the campaign but that it follows them.