E2E usually means from endpoint device 1 (my iPhone) to endpoint device 2 (my friend’s iPhone). What the other person will do with it doesn’t factor into the conventional definition of E2E.
No, conventional definition is actually both: from endpoint device 1 to endpoint device 2 and from endpoint device 2 to endpoint device 1. If device 2 has backups in question enabled, there is no E2E anymore.
