>>11706321The character's existence is dependent on its effects on the world around it. Whenever Gura uses her public accounts to interact with her environment, that is proof of existence. Simply having a schedule that details her next appearance influences her viewers and the world around her.
If Cover could find a VA that was talented enough to mimic Gura in some capacity, then the character's existence could persist. Kizuna Ai is an example of this despite the poor execution.