From the outset, Microsoft has emphasized that Windows 10 will be treated like a service, unlike previous releases of the operating system. This strategy will allow it to update Windows 10 on a regular basis, to ensure that the best security and bug fixes can be deployed rapidly.
Microsoft's most recent version of Windows for mobile devices, Windows 10 Mobile, has recently shipped on multiple handsets and is scheduled to arrive on older devices next year. The company's methods regarding Windows 10 Mobile updates have been questioned in recent months, due to restrictions imposed by cellular carriers.
In response to a post on the AT&T forums, a company representative has reaffirmed that Windows 10 Mobile updates won’t be certified by AT&T (and assumedly any other carriers) for a faster rollout across handsets.
“The 950 will be receiving monthly WaaS (Windows as a Service) updates, and the latest one released on December 8th (Build Version 10.0.10586.29.) These updates are not certified by AT&T, and will be delivered via Microsoft over-the-air. A Wi-Fi connection is required. From the App List, scroll down and tap Settings > Phone Update > Check for Update.”
This comes as good news for many Windows Phone users, who have previously seen updates held back by cell phone providers. With these new agreements, Windows 10 Mobile updates can be pushed without the authorization of carriers, but firmware updates will still require approval before being deployed. This results in some firmware updates, such as the recent firmware build for the Lumia 950 and 950 XL, seeing a delayed distribution on certain networks.