Exactly. They simply have several parallel universes to allow for more artistic freedom, but the original universe hasn't been abandoned. It's just not used that much anymore since there's already so much stuff built on top they'd have to take into account.Just see Gundam as the example. When their prime universe, The Universal century has become old,
Not so much since they have a currently running OVA set in it and have plans to do an adaption of a manga retelling of the original show.
Yeah but they are kind of rebooting it.