Interviews are mainly called for when IRCC suspects a Marriage of Convenience; there are a ton of different things that could lead a VO to suspect MOC, such as different language/culture/religion/education levels, marriage on the first visit, no time spent together in person, age differences etc. For obvious reasons, people from countries that are equally as developed as Canada, such as NZ, are not MOC risks.
Interviews can also be called for when there are other serious red flags such as criminality, misrepresentation etc.
That makes me feel better, I also though that him being from a similarly developed country would decrease the chance of an interview.
Neither of us have a criminal history, he didn't overstay when he was in Canada a few years back. We're an interracial couple and he's a year younger than me, but I'm assuming that isn't much cause for concern. -hopefully. We will have been together for four years in May and got married earlier this month, waiting for marriage certificate to be mailed to us so I can send that through the webform.
I started over thinking too much. Thank you!