You need to continue to use your old Roon core until/unless you have another computer device that you can install Roon core on. You cannot install Roon core on your Cambridge CXN V2.
If you have more than one computer device capable of running Roon core, you can run the Roon core on multiple computers, but you can only authorize one at a time. I have my Roon core on a Roon Nucleus for use at home and on a Dell laptop for use when I travel.
Yes, you can use your Macbook Pro to run Roon core.
An out of the box cxn v2 might need a firmware update to enable roon ready, there is probably a setting also in the cxn v2 menu to turn on the roon ready option.
Thanks! 
But it still can’t run Roon core.
Thanks for letting me know!
CXN V2 owner here. I didn’t need a firmware update to connect my roon core…
I know! I was advised wrongly 
Thank you for your time trying to help me!
Might depend on the age of the stock you get. More recent ones will have latest firmware pre installed - I noted as its a new unit for a new user.
I bought my CXN V2 about one and a half year ago… doubt it has anything to do with the firmware to be honest.
For some reason with some older Roon releases I first had to open a remote session from my Macbook Air where the Roon Client is installed on my Mac Mini were Server is installed before the Client could find the CXN V2 under devices. The system did not behave like that when I started using Roon and this bug suddenly disapperead again after a few releases…
it was indeed a firmware update in Feb 2020
Depends how current you are , I apply all as soon as they show . The CXN will nag you otherwise
Thanks!