You have to remember how the process works at VCU. Everyone is ranked based on their score and once a decision date rolls around they offer acceptances to the highest ranked applicants. If you didn't hear something on October 15th, it doesn't mean that they didn't finish looking at your file; it just means you weren't high enough on the list to get an acceptance on that date.
Again, not everyone who interviewed in September got news on October 15th, only those who were at the top of the ranking list did. This means that, for December 15th, if someone isn't ranked highly enough to get an acceptance, even if they interviewed months ago, they may not hear anything.