One interviewer was a data professor, yeah. The other was someone on the admissions team.
I applied to Studio 20 at NYU. Columbia's data program is definitely my #1 choice though, fingers crossed on that one.
I'm not sure how common it is to be interviewed. From everything I've researched it seems to be more common if you're applying to a specialty rather than the general program, at least in the case of the MS. Haven't found anything on the MA though, but I wouldn't assume that an interview is required unless you've heard otherwise from others applying.