maybe they trew out hinata so she can improve herself before continuing the training under the main famalie, and they decided to keep hanabi and train her, since she is already fit to train under her father.

but hinata is the heir, so some day she has to become the strongest of the hyuga. so training from her father should contineu some day.

i really hope they explain more things about the hyuga soon. the hyuga is really getting an interesting clan.