We've had more than enough opinion from the Muslim world that the niqab is not a requirement of Islam. 
The niqab is more prevalent where the strictest male-dominant interpretations of Islam exist. 
Many nations, Muslim and Western, that aren't interested in nurturing "society within a society" Islamic enclaves have banned it's use. 

The adoption of the niqab by young Canadian-born women is nothing more than social "Hey everyone- look at me!" envelope-pushing so indicative of the identity politics movement. 
The religious adherence angle is supposed to legitimize what is essentially a fashion statement. 
They think Bill 62 gives them potential victim status which is even better.