While this isn't exactly an unexpected event, Microsoft has confirmed that Windows 10 Mobile will not receive the Windows 10 Creators Update at the same time as PCs.
In a statement to Softpedia, a spokesperson for Microsoft said:
The initial update will be for desktop, but other versions will be available thereafter
If it's anything like before, it could be weeks or longer before the Creators Update gets around to all the Windows 10 Mobile users out in the wild.
The Windows 10 Creators Update is expected to be RTM this month and be available to retail customers by April, for Windows 10 PCs.