Campaign mode basically only saves checkpoint/quest/waypoint progress. It doesn't remember what mobs you killed or even what spawned. Assuming they aren't going through the work to implement full zone saving just because you complained about it, you can't really get much more than remembering which bounties you did towards completing an act. For example, saving rift progress wouldn't work because you could just farm the same rift mobs all day long minus the rift boss.
What would be more reasonable/likely is a reconnect feature. Keep a game alive for a short time if it would've ended due to disconnect, and let players rejoin it on login. Wasn't something like this eventually implemented in D2 even?
What would be more reasonable/likely is a reconnect feature. Keep a game alive for a short time if it would've ended due to disconnect, and let players rejoin it on login. Wasn't something like this eventually implemented in D2 even?