I believe so.
The Concert 2+ uses the same Quadlock connector, and the Audio in (for the speaker signal) and the "telephone active" to make the screen say "PHONE" and mute the incoming audio, then switch to the phone kit signal) are on the same pins for both Concert 2+ and RNS-E.
I kept my Parrot Evolution 3000 Buetooth kit when I switched from Concert 2+ to RNS-E, and it worked just as well with the RNS-E. It uses the phone active ("mute") line and the same telephone audio "hi" and "lo" pins on both.
Mind you, the OEM bluetooth is an upgrade to consider town the line, particularly if you have a MFSW and DIS... with both of those AND RNS-E, the combined difference between aftermarket kits and OEM is massive. Being able to scroll through contacts in the DIS from the steering wheel, ans see incoming or call-waiting info coming up on the RNS-E is fantastic! -My Parrot couldn't match that.
But in answer to your question; yes. RNS-E should continue in a similar way to your current Nokia CW-7K, while allowing you the option to take further advantage of the OEM system, in case you ever decide to upgrade later on.