This study based on a sample of 81 niqab wearers indicates they are not being forced to wear it and the majority had no issues showing their faces for security or safety reasons.
http://ccmw.com/women-in-niqab-speak-a-study-of-the-niqab-in-canada/
The legislation should have reflected this.  It would have satisfied most people, including those in Quebec.  There is no need for a woman to stay unveiled longer than necessary.
 To date, there has been no discussion of employment probably because there are so few niqab wearers and most are homemakers.  What's going to happen when some applies for a public facing  job wearing one or what's going happen when someone applies for a job without one and starts wearing one once they get the job?  An employer is supposed to make every reasonable attempt to accommodate religious beliefs.   It's not a problem now but if  the number niqab wearers grows it might become one.