The Triad has a very large Hispanic population - particularly in the younger demos. I think you will find those that migrate to the US (legally and illegally) are generally younger adults with small children accounting for the tremendous growth in the 18-34 cell. I suspect there are relatively few Hispanics is the 35 plus cells.
It is likely that close to 100% of the available Hispanic cume is now reporting that one station. Meanwhile, the English speaking cume is scattered across a number for formats.
The other factor is that for years, the Hispanic group has been scattered among all the small, AM Hispanic stations - none of which garnered enough in-tab listings to register in the Arbitron. Now they have gravitated to the one station with a metro sized signal.
For Arbitron purposes, it is all NEW CUME and therefore, the big jump for the station that didn't exist before.