XEP-Remarks/XEP-0352: Client State Indication
No Beacon signaling when the client state changed fully to activated
Certain use cases require to determine when the client state has been changed to "activated" (i.e. for most implementation when the last flushed (presence) stanza has been received). Imagine for example an client which determines the receiving JIDs based on presences. First this clients sets CSI to active and then it has to determine somehow when the presence information is up to date.
It would be sufficient if the server would send a beacon message like
<message to="email@example.com/resource"> <csi xmlns='urn:xmpp:csi:1'> <activated/> </csi> </message>