^ Meh. That makes sense if you assume all possible actions create new timelines. I'm of the opinion that such is not the case and divergent timelines only come into play when gigantic changes happen to the universe like Vulcan being destroyed, for example.
However, Admiral Janeway going back in time did not cause that kind of monumental change to the universe, IMHO.
I see, so basically we assume what happened with this finale is that the quicker Voyagers crew experienced the SAME things, only earlier than before. (and that 7 and Chakotay will have a relationship..etc.)