Windows 10 Mobile Anniversary Update is not coming today. Head of the Windows Insider program Dona Sarkar has confirms it on Twitter:
@thiago12317 Not today. We need a bit more time to get everything running the way we like.
— Dona Sarkar (@donasarkar) August 9, 2016
Microsoft already released Windows 10 Anniversary Update for PCs a week ago, and summer updates for both the Xbox One and the HoloLens. Windows Mobile Insiders already have Windows 10 Mobile Anniversary Update build 14393.5. It is possible that today Microsoft could release cumulative update (build 14393.10) for Mobile, as PC build is already at 14393.10.