I've been testing this, and while Cinder does indeed not understand the 2.11 cinder:// urls, this bug doesn't "break" Cinder because when Cinder can't find the volume containing the image, it just downloads the image from Glance and creates the volume that way. So while the bug prevents Cinder from using the optimized work flow, it doesn't prevent creation of volumes from images.
I've been testing this, and while Cinder does indeed not understand the 2.11 cinder:// urls, this bug doesn't "break" Cinder because when Cinder can't find the volume containing the image, it just downloads the image from Glance and creates the volume that way. So while the bug prevents Cinder from using the optimized work flow, it doesn't prevent creation of volumes from images.