The Void Zombie has no special attachment to the Akata that created it, though it likely possesses the 'helpful' or 'friendly' attitude relative to its parent in most settings. Void Zombies, however, are classified as Undead, and so subject to the Command Undead feat (and similar abilities), allowing a caster so inclined to control them (and keep them after the summoning expires, which is a nice bonus!).
Furthermore, the default behavior of Zombies, according to the cursed item Gravesoul Armor, is to "mindlessly attack unassociated creatures near them". It is possible that the GM would rule the summoner an 'associated creature' and exceedingly likely that the GM would rule the parental Akata, other Akata, other Void Zombies of the same brood, and other Void Zombies in general "associated creatures" and thus not subject to the Zombie's default 'kill everything else' targeting.