Mine did have my name and address pre-filled in after I entered the code.When I did mine, it spat my address out at me and asked if it was correct after I had entered my phone number. I figure that's because each serial numbered census form is "married" to an associated civic address in their database before we even start to fill them out. But it might be from public telephone records they automatically searched soon as I input my phone number. Dunno. But I do know that the website did NOT offer a guess as to my name.
Maybe you are half-remembering what it already "knew"? Unless you spoke to an enumerator and they noted your name and address in the database (which happens in rural areas where they deliver the census forms by hand rather than rely on Canada Post), I'm pretty sure that the website did NOT offer up your name until you had input it.
It did not link up my name and address after entering a phone number because for the phone number I input.... 555-555-5555.
It can't be from public telephone records either because I don't have a public phone. I only have a cell phone. I haven't had a land line in over 10 years, in which I have moved twice since then. The only way they'd match up some kind of name/number is if this census was done 2002. I haven't showed up in any kind of yellow/white pages directory in over 10 years.