Re: Endgame and the Unicomplex (spoilers)
I hate Temporal mecahnics.
But what should have happend is in the future starfleet would have monitored Janeway's escapdes and sent back people to undo her changes. After all VOY introduced the concept that in the future the Federation monitors the timeline so "Endgame" should never have happened and VOY should still be on her way home.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.