Light and sound are very different. Sound is actually a mechanical disturbance through air or another medium. Sound always needs a medium to travel through and the type of medium determines its speed.
Directionally you never know where a balloon is going to go because the wind controls it, I don’t. I can send a balloon higher or lower, but not steer it in specific directions. So before we send passengers up in a hot air balloon, we send up a small hydrogen balloon that tells us the wind speed and direction.
De-extinction, as it’s been termed, hasn’t happened in over 3 billion years of life on earth, so it will be an epic event if and when it happens.