Yesterday it was released upcoming Windows 8.1 Update 1 on the internet and even with Microsoft links, allowing users to freely download it from its servers, even if its official release is expected to take place next month.
The company immediately after leakage, moved very quickly and disabled the addresses that allowed users to download the package through Windows Update.
Of course, this is not problem since the MSU installers released by Microsoft since yesterday are available throughout the web.
Maybe of course it was a Microsoft communication trick waiting to see comments and reactions before the upcoming release expected from MSDN 1 or 2 April Day for Developers and Consumers in 8 April along with other updates that will come with Tuesday's Patch.