Even after end of support, automatic or manual creation of new device backups for setting and some applications will continue for 3 months, ending October 11, 2017. Other services including photo uploads, restoring a device from an existing device backup and the Store will continue to work for at least another 12 months from end of support, after which time, services will start to be discontinued.
https://support.microsoft.com/en-za/help/4036480/windows-phone-8-1-end-of-support-faq
https://support.microsoft.com/en-za/help/4036480/windows-phone-8-1-end-of-support-faq