I spoke to Columbia less than a minute before this message and asked if more interviews would be sent out. The exact response I got was "We sent out interview requests, we may send out more, we just don't know." I asked again, "Is there an actual possibility you will send out more requests?" she said "Yes." There's no way of me knowing if that's PR to ease the pain, but those were the responses a few seconds ago.
Edit: To add to this, she also gave a line that resembled "In the past we have sent more interviews out after this stage." which confirms that the previous year spreadsheets of different interview request dates is in fact accurate and there was hope for those at least within that year/potentially within other years. So if her information is correct, the "doubt" that the spreadsheets of previous years were incorrect, can be settled in the event that this admissions officer is competent in relating information.