Today, Microsoft announced that the Windows 10 Creators Update is now available to everyone. Since the company only supports the two most recent feature updates for the OS, it also confirmed an end of servicing date for the first Windows 10 feature update, version 1511, also known as the November Update.
That date will be October 10, 2017, and obviously Microsoft recommends that if you have a machine on 1511, that you upgrade it to a newer release. Unfortunately, there are still consumer PCs out there that haven't been offered a newer update, and for those, it's recommended that you manually initiate the upgrade.
Presumably, this is meant to imply that there will be no more cumulative updates for that version of Windows 10 after October's Patch Tuesday. However, the firm promised to end support for the original version of the OS, 1507, in March; then delayed it until May; and still continues to offer updates.
Microsoft also updated its Windows lifecycle fact sheet to reflect the various feature updates to Windows 10 (currently including 1507, 1511, 1607, and 1703). To be clear, these dates reflect the end of support for Windows 10 Home, Pro, Enterprise, and Education, so Mobile is separate.