Microsoft have released a fresh version of build 15063 of Windows 10 Mobile (15062.2). The new version fixes one issue which is the ability to update to this build from the standard Windows 10 Mobile Anniversary Update (build 14393).
I are pretty certain that 15063 will be the version that rolls out to general Windows users and this point update to 15063 backs that up. The update still seems to be a large download despite only containing the one fix and I imagine with this fix released Windows 10 Mobile is ready for general release.
UPDATE 3/28: We have released Windows 10 Insider Preview Build 15063.2 for Mobile to Windows Insiders in the Fast ring. This build includes a single fix to enable the ability to update to Build 15063 from the Windows 10 Anniversary Update (Build 14393) on Windows phones.
Here is my hands on video with 15063 for Mobile: