Yeah, this is weird. I saw it as well. I'm fine with no pools in the base game but no toddlers? But It seems they plan on adding them later in the Expansion Packs? LOL
I'd rather have toddlers and not young adults then. Doesn't make much sense... But maybe the babies aren't like the Sims 3 babies, they might be bigger and idk, do something.
Also something great is that the sims will be able to live in one world and travel to another one (that takes a loading screen) I'm quite happy about that, since it was one of the features I missed the most in The Sims 3! Neighborhoods in the same world will also be separated by loading screens, which makes the game less 'heavy'. Just hope those loading screens don't take hours.