I'm sure it does to some degree, though I don't know if it's enough to matter on modern computers, and isn't that what flatpak does, too? (duplicating dependencies)
In any event, if you don't need an application from a specific distro there's no reason to create that container. The non-ubuntu ones get created when they're needed. (And I think the next version of VanillaOS will be debian-based, not ubuntu; in case that matters.)