Since each passing moment would mean we are one step closer to the RTM build of Windows 10, Microsoft has started to make requests to Windows Insiders to stick with the currently installed build, and that means the suspension of the availability of Windows 10 builds. Not only that, Microsoft is also working on suspending both ISOs and activation.
Gabe Aul did mention on the Windows blog, “We’re suspending the availability of Windows 10 builds briefly while we prepare for that, and the next build that we flight to you will be delivered using the production channels. Starting tomorrow, we will also not be delivering any additional ISOs at this point as we really need Insiders to be using, stressing, and validating our distribution and upgrade processes. We’ll make ISOs available again in the future, but for now we ask you to upgrade your current build via Windows Update once the next build is released.”