It’s expected that Microsoft will officially release the Windows 10 Creator Update on the 11th of April, but it’s likely most users won’t receive the update on that date. Microsoft will most likely gradually distribute it to users of its latest operating system.
The update, previously known as Redstone 2, will probably be slowly distributed to make sure Microsoft’s servers won’t be overloaded and so the software giant can stop the upgrade process in case a serious bug is found.
Also the Windows 10 Anniversary Update was gradually released to users, a graph from AdDuplex (via PCworld) shows it took 4 months before about 80% of all Windows 10 users had the Anniversary Update installed. Within the first 2 months after the release about 33% were up-to-date.
Even today not 100% of all Windows 10 users has updated to the Anniversary Update, it’s unclear why.
Obviously the gradual distribution doesn’t mean users who are eager to update have to wait. It’s possible to force the update by manually checking for update or installing an ISO file.