You seriously don't think they're going to regularly add content once the game launches Kachi?
You seriously think they'll be able to add enough to keep pace?
Of course I'll admit that I could be wrong, but my guess is that if they're creating all new content from scratch, it won't be enough. Think of it in terms of FFXI. XI didn't have enough content upon the JP release to prevent players from finishing it, and that game was slow as ****--it would never hold the attention of a U.S. audience. There's a tradeoff that's made in pacing a game that waivers between boring your players throughout the game vs. letting them do everything soon and be bored when its done. When you don't rely extensively on emergent mechanics, this is inevitable. Finding the best middle ground is all that they can do, but at the end of the day, you can't solve the pacing problem without more content.
It's like surviving a famine. You can stuff your players at the start and let them suffer on their own fat when they get to the end, or you can string it out, letting them go hungry every day. And somewhere there's an optimal rationing to keep them in the best possible shape, but at some point, no fancy rationing will save you. When you're out of food, you're out of food. A trickle of new rations here and there won't cut it.