With Urasawa's standard pattern of 8 chapters per volume, I have a strong feeling that we will get chapter 16, and then he will take a hiatus for a few months. We do know that volume 2 will be printed in early autumn 2019, which I bet means it will be out in October. The story has another 56 years to go before it catches up to the events shown in the first chapter, and I'm so excited to see where it goes!