In V11, our organisation has a large number of long running chatter threads connected to various objects.  When employees arrive at and leave the organisation, it takes a long time to manually remove and/or add the employees to the lists of followers for each of the relevant threads, and invariably, I miss some of them, so new employees might miss important messages.

I know we can use channels, and add those channels as followers to a given object, but it seems that if a message is posted to a chatter thread, individual users don't have the message show up in their inbox.  They have to proactively visit the channel to check for new messages.

Is there anyway that this can be changed?  A third party module perhaps?