You are correct that all milk undergoes a homogenization process, but for whatever reason, only 3.25% milk is labelled as "homogenized" in Canada. Even the ingredients/fine-print are like this too, so it's not just a marketing thing [0] [1].
This could be a regional thing though: out east milk typically comes in bags [2], but I'm in the west and have only ever seen milk in bottles, so it wouldn't surprise me if the term for 3.25% milk was different in the east too.