Not-yet-released and Out of Stock items aren’t the problem you think they are.
There are thousands of customers online right now looking for their favorite products, and they don’t mind placing a pre-order to eventually get what they want.
What those customers don’t want is an unclickable out-of-stock button that shuts them down and sends them back to a search engine to look for another option.
If you can position your store as the one place that will let them buy today, or even order before it becomes available, you will increase your average order value simply because you’ve eliminated an assumption about what customers are willing to pay for.