I believe most users will expect sound, and if there isn't they might feel something is wrong with the app (either with their version of the app or the app itself). Even if most users don't want the sound, I think that is an opt-out decision. So you might probably get complains from users telling their app is not working correctly, because if there is no sound they might think something else might not work correctly.
You can go on without sound, but I would inform the user it is intended and tell them why. You could make this an advantage, but you would have to sell it well (give an acceptable reason). A spy game where silence is part of the experience? Just an example, but if you decide not to include sound: tell the user and tell the user why. Even if the sound is not 100% part of the game experience it might feel weird.
Also consider that when releasing an app the first days are the most valuable. It might be worth waiting to create a better impression. But the timing is also important, so also consider this. For example if you were going to release a Christmas app, it might be better to release it without sound the day before Christmas than a week after with sound.