Yes, the update deleted my sparsebundle on my NAS, and Time Machine insists on creating a new one on the network share. It can't, of course, because it's a network share. Time Machine ignores any new sparsebundles I copy over to the network share and absolutely insists on creating a new one itself.
I haven't got my backups to run again after this update. I think I'll try creating a backup on an external hard disk to see if that can shake Time Machine from its obsession with creating a new sparsebundle.