Hello!
Yes, you need to enable NPIV for NetApp cDOT.
"Clustered Data ONTAP uses NPIV to present Fibre Channel targets to a fabric. Make sure to use an NPIV-capable switch and to enable NPIV functionality. For details on which environments are supported, see the online NetApp Interoperability Matrix."
And think there is no problems to connect cDOT and 7 mode NetApp to same SAN switch.