Microsoft have confirmed that Windows 10 Mobile Creators Update will start rolling out from April 25th. Starting a couple of weeks later than the PC version the phone version will be phased rollout with availably depending on device, mobile operator and country. Mobile OS updates tend to be a much more protracted affair than the PC rollout as mobile operators get involved, in some cases devices get updated promptly whereas other may wait months. Having said that Windows 10 Mobile rollouts should be simpler due to the low user base.
Windows Phone will follow the same phased approach, with rollout scheduled to begin April 25. Note that update availability may vary by manufacturer, model, country or region, mobile operator or service provider, specific installed software, hardware limitations and other factors such as feedback from customers.
I have been running the fast ring builds of the Creators Update for some time and while these aren’t as many changes to the phone version as there are with the PC version it has been very stable.