The Verge learned earlier this year both that the Start button would be returning and that a boot to desktop option is being considered for the coming update. Thurrott is also reporting that a boot to desktop option will be included, but that it will be turned off by default. Though Microsoft is yet to confirm that either of these options will be present in Windows 8.1, this new leak certainly helps to further substantiate the Start button's return.
Read More: Windows 8.1 Start button shown in leaked screenshots | The Verge