The Paranoid Gamer writes: "Even though it’s up there in massive capital letters in the title, I feel inclined to warn you again that we will be discussing massive spoilers that will include the ending of Assassin’s Creed 3 (and possibly other games within the series). If you haven’t finished the game yet I highly suggest you do so before reading any further."
How they continue the franchise was down to Connor's feedback (Ubi have come out and said depending on the feedback about Connor will dictate if we will see him again in a future AC game). If Connor's feedback was good then they would have to do some lame " o look Desmond not dead" or "o look here is a relative we could have used before but we didn't" (the feedback from what I have seen has been less favourable).
I personally do not see them going to the first civilisation for a whole game (maybe snippets). I see the next game setting a little bit in the future from AC3 where the gang have found a new protagonist who will use his memories to find certain pieces of Eden to finally over throw Juno. I just think that's the most logical step forward
I personally didn't fully like the ending to AC3. I could see it coming a mile a way and I knew they had to kill of Desmond because they said it was the end of his story and he couldn't just survive and then retire in the hills somewhere.
Also is Desmond really dead? I know the thing was supposed to kill him, and he is shown lying on the ground motionless, but we aren't shown anything after that. Plus there's tht point that you still play as Connor for the epilogue. And you're definitely still in the animus given the whole pivot thing.
Another thing, you really don't get much of a sense that the world is about to end. Sure the characters say it, but I feel like there should have been the odd tremor or something.
And no, the second option would have sucked. I think the point is that the First Civilization could predict exactly what would happen (they seem to be beyond time), so that IS what would have happened. How is basically repeating the same patterns of human history better than moving ahead?