If a VLAN is attached to an I-SID there must be another instance of that same I-SID in the SPBM network.
If another instance of that I-SID exists, the device designates that VLAN as operationally up regardless of whether it has a member port or not.
When the VLAN is operationally up, the IP address of the VLAN will be in the routing table.
If no matching instance of the I-SID exists in the SPBM network, then that VLAN has no reachable members and does not act as an NNI interface.
The VLAN does not act as a UNI interface because it does not have a member port.
Therefore, the device does not designate the VLAN as operationally up because the VLAN does not act as a UNI or an NNI interface.
If the device acts as a BCB with two VLANs configured and two I-SIDs, there must be a UNI side with the corresponding I-SID existing in the network.
If the device acts as both BEB and BCB, then there must be a member port in that VLAN to push out the UNI traffic.