Of course you will not activate BF Telco on live ECC production landscape! 
Exact scenario is main reason for existence of preproduction landscape where you migrate data from production landscape and test activation of Telco business function in order to identify and prevent possible risks.
As I see it, telco function activate telco specific elements in ECC and you will activate it after extensive tests on preproduction.
But in order to have full BRIM functionality you will have to install and integrate SAP CC and SAP CRM or Hybris.
Br,
Mario