From Microsoft's blog post:
This is just a sampling of the many innovations and offerings we’re excited to deliver with the Windows 10 Anniversary Update on August 2. Upgrade today before the free offer ends July 29 or take advantage of one of the amazing new deals on a new Surface or PC so you’re all set to enjoy it this summer! Thanks again for all of your support for Windows 10; we’re committed to keeping the innovations for you coming!
Throughout the last few months we've been used to seeing the Redstone (Anniversary Update) Insiders builds of Windows 10 be in lock step, more or less, for desktop and mobile, begging the question of what will happen for the phone on August 2nd 2016?
Not a lot, at least for production handsets. Which sounds like a disconnect with desktop, but it's not really:
- late July 2016: Microsoft decides on a stable build for Windows 10 from the Insiders rings and this becomes the first OTA for the Anniversary Update for the desktop. Mobile Insiders are also on the same build, for both Fast and Slow rings (in fact, Fast will probably be ahead by August 2nd). Also, the 'Release Preview' Insiders ring is switched from Threshold to Redstone (marking the point where the old x20 Lumias get left behind in terms of being able to get to Windows 10 at all).
- August 2016: final testing is done on phones with this build before it's included in OTA updates to production handsets (think Lumia 950). OTA updates to the Anniversary Update start rolling out to production handsets/users, i.e. non-Insiders. Microsoft: "It will take some time since there are a *lot* of machines globally to update". Think weeks.
- mid-August: OTA rollouts continue to those who upgraded to Windows 10 from 8.1 (think Lumia 830, 930).
So Insiders do get to be in lock-step with the desktop, but the extra complications of updating mobile OS images add a couple of months weeks to production OTAs. At least, that's how I read it! Given the number of issues people are still experiencing with Windows 10 Mobile Redtstone 'Fast', I'm a little sceptical that the build on August 2nd will be stable enough for the phone and suspect that things like Wifi and Bluetooth stacks will still be being tweaked right up to the last minute. Sigh.