Honestly (and unfortunately) I don't think we're getting a Generations pack. Instead, I think they will spread it's content in smaller packs.
We got Parenthood, kids stuff, toddler stuff, now we'll be getting some elder stuff in the knitting SP, and then we'll probably get a teen pack. Plus they can add things in updates as well.
Don't get me wrong, I know this is not enough, but seeing how they've been cutting content from packs to make more money with other packs, I guess that's how it's gonna go. Plus they said people don't play with kids and Parenthood didn't sell that much (despite being loved by the community). So yeah, not much hope for a Generations pack.