The point is that it shows you what happens in the future. The idea this season was that by connecting the universes via the bridge, the red one could heal and, as we saw, it has been working. By skipping ahead, we get a taste of what happens after both universes are back to normal AND we get to see a new side to the observers. It's a complete role reversal for them (which has become a very common theme in this show) and rather than just be on the outside looking in, we see that they have the capacity to completely change how they interact with the world. Not only that, but it opened the door the future, leaving them free to completely finish the current plotline and give us closure, whether or not they got a chance to continue past this season. It was a really smart move and, at least for me, it presented very interesting prospects on what could happen in the future.