Windows 10 1803 release via Windows Update during Build

Just wondering, why did Microsoft decide on May 8th as the day in which Version 1803 starts rolling out to those of us on Version 1709? Don’t they usually stream the Day 2 keynote as well? Considering the internet traffic going to and from Microsoft’s datacenters once 1803 starts going out on May 8th, will there be a staggered rollout as there was with 1709 and 1607?