There isn't a hard cutoff, those are the recommended grades to receive an offer. I'm currently in the Computer Engineering program here and I can say out of my class, most had around a 90. That said, CE is one of the less competitive programs.

Here's a chart of the number of students rejected from Waterloo Engineering with averages 90+: https://profbillanderson.files.wordpress.com/2014/09/unadmit...