I think....
Platform is the underlying UCOS code base and it's tables to make certain platform functions work.
admin:show dbreplication runtimestate
Enterprise or Application repl is the UCCX data base replication for things like document/config/historical/etc.
admin:utils uccx dbreplication status
If the former is broken, I do not believe this breaks your UCCX. If the latter is broken, I believe it does. As far as affecting CUIC, I'm not 100% positive, because there are so many aspects of CUIC: SocketIO for Live Data, Scheduled Reports, Purging, Historical Datastore, etc.
Maybe someone else can enlighten both of us on that.