The Bittervets wasn't a planned event, in fact it slowed progress on many features because it uncovered issues with the underlying infrastructure; which is of course a good thing.
I've pointed this out before and everytime people call Doom, AC made a business decision to launch the game, probably for fiscal reasons. Minecraft isn't out of beta yet but people are paying for it which allowed Notch to continue developing it. That wouldn't have worked for Perp, so they launched and are continuing to develop the game.
The Perp game doesn't 'require' the current player base to continue playing. From the most syncial standpoint, we did our job by paying the bills to allow the develpoment to continue. Realistically AC doesn't want to lose the vetern player base, but they simply can't produce content instantly out of thin air, so if we lose interest and leave while they finish the content than we do.
The game was reasonably stable at launch, it was a good decision. It may take 2 years for all the content to be ready for a huge launch, or maybe it will be done this month. Either way when it is ready, and AC makes a big advertising push, they will get players to come. The only thing that's going to kill Perpetuum is if AC chooses (or is fiscally forced) to stop improving it - and with so much already invested I don't see either of those happening for atleast another 12 months.