[jkepler]

But if Signal only used the phone's contact list, and only stored it locally, and if a user independently backed up her contact list, wouldn't that mean in the case of phone loss, Signal could rebuild its contact list once the user restored her contacts to the new phone? Am I missing something?

[PaulDavisThe1st]

i.e. it's not Signal's job to provide a backup of the phone's contact list. Bravo.