Which agent told you? You mean the officer at the interview ? That’s what I was told by the agent on phone at CIC call Center about cases not being called “non routine” anymore after 2015. Actually , if you search on Canada.ca site, they mentioned similar thing too as in if someone applied before 2015 and still hadn’t got the citizenship yet, it would’ve been considered non routine .I am not aware of cit0520 however the agent himself told me that if normal processing time passed than the case become non routine. I googled non routine case and got freaked out
Every case and situation is different. Do not worry too much. That’s what I keep telling myself and others too. At the very least, we can keep renewing our PRs to get with our lives while waiting .