Mine 4 friends citizenship process completed within 6 months with test and oath ceremonies and we don't knw what happened wrong with your friend's file.Sounds like something is fishy in story.Nobdoy wait that long.Every file is different.
Pretty sure there is nothing wrong with his file. It's just that the Kitchener office is really very very slow. Have a look at the excel spreadsheet for people from Waterloo, Kitchener, Guelph or Cambridge. No one from April 2018 applicants and after has received test invitations. They are most likely working on March 2018 right now and should get to April soon. But November is a far time away as far as Kitchener is concerned.
Saskatoon office, on the other hand, is quite quick in processing applications. Even August 2018 people from Saskatoon have received test invites!