The Masked Authenticated Messaging Introduction doesn't talk about snapshotting as it relates to MAM data streams, so I am trying to work out in my head what happens during a snapshot. It's a forward only set of linked messages. If all of the messages have been culled from the tangle by a snapshot, then the stream is pretty difficult to read obviously. But can a new message be added? For a private root, I don't think that's possible, so that seems particularly bad.
Obviously a permanode would not be impacted by the snapshotting (it's got everything), so is the only use case for MAM streams that need to live for an extended period of time - or through a snapshot at all really - to use a permanode? Both the sender and receiver would need to use the permanode as well in the case of a private root, correct?
Am I misunderstanding what gets lost in a snapshot or will there be special considerations made in snapshotting to accommodate MAM in the future?