Yes, unfortunately the technical side of making topics “bump” up the list for a subset of users is pretty tricky. At the moment we only have one record of ‘bumped timestamp’ per topic, and so it must be the same for all users. It might happen eventually, but for now whispers do not make a topic bump up the ‘latest’ list.
However, they will make a topic appear “unread” for staff, if they are tracking the topic. And they will trigger notifications/emails as normal.