Again, not aiming for that age range and having absolutely nothing for that age range is not the same thing. I'm not saying they're out there trying to actively discourage any families with younger kids coming. It's just not what their focus is, while for Disney families with younger kids is their primary aim.
And the lands you mentioned, Toon Lagoon's two rides have height requirements. Heck, one of them has a crazy restraint because its drops are so steep. When it opened, Seuss Landing's main ride spun like a washing machine on steroids. Volcano Bay has two kid areas, but, to be honest, their slides are all pretty intense compared to the local competition (though to be fair it's been like a decade+ since I've been to Aquatica).
Yea, all those lands have some stuff for very little kids. But outside of Seuss, I wouldn't say any of them are focused on little kids.