This is all based on my conjecture and some experience making RPGs, no insider insight.
So that's the engineering team largely committed, right?
Well, I see it as a diversity play. Arguably all the people who are going to be "into" Elder Scrolls or Fallout are into it. There's lots.
Well, first, it's reusing assets, reusing engine, reusing setting and concepts.
In a way, we're all entering the vault program by playing.
We're all Vault Dwellers now.