Columbia asks you not to email admissions as the alumni network handles interviews. The volume of applicants in your area may be too great for the number of willing alumni volunteers. Interviews are assigned without any bearing on the merit of the applicant and the lack of an interview will not hurt you admissions-wise. Just relax
we have a month until decisions
In case you are still obsessing, it is my (completely unprofessional) belief that interviews have little effect on the overall application. The interviews are conducted by alumni volunteers and are less evaluative and more conversational. In my opinion, the main benefit is to the applicant as you can ask personal questions about Columbia life. Do you know any alumni? Perhaps they can answer some questions for you.