I did not have my interview, I just went up to the Professor and asked. The final decision on all the scholarships will be made by ETH's rector Sarah Springman and not by the professors who reviewed your application/conducted your interview. I asked the study administration for Data Science about the procedure regarding admission to the Master's program and ESOP so you can try contacting the corresponding people at your department.
I talked to a Professor at ETH today and he told me that the internal deadline is mid-February. So I guess if you haven't had your interview by then chances are pretty low.