I got this Email today
We previously notified you of the date and time of your immigrant visa interview at the U.S.Embassy/Consulate General in MOSCOW, RUS.
Due to unforeseen circumstances, we have to cancel this interview. We will schedule a new interview appointment as soon as possible and notify you of the date and time. There is no need for you to take action at this time.
If you have any questions, please contact us by following the instructions at https://nvc.state.gov/inquiry.
Regards,
National Visa Center,
U.S. Department of State
However They NEVER NOTIFIED US of an Interview!