When the command monitor session 1 destination remote vlan 223 is added to the configuration, it replaces the existing RSPAN VLAN destination with VLAN 223. This is because a monitor session can only have one remote VLAN destination at a time. If there was already a destination configured, such as VLAN 222 in this case, it would be overridden by the new command specifying VLAN 223. References: Cisco's official training and certification resources on Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR).