Where is the "Highland RF facility"?
While it's not named as such in the licensing process, there are no other 700Mhz licenses issued for Dallas other than for the Dawson Road, Florina, and Frankford locations, with associated mobile frequencies. I'd guess that they are referring to the Frankford Rd. site as "Highland". Dawson is the main site downtown, and was of the first completed. Florina, in s/w Dallas County. was also on-line in time for the Super Bowl. The Frankford site might have been sidelined in the rush to get the NCTCOG interop overlay done, since coverage in that area would also be provided by the Denton & Collin County sites.
All of this is, of course, my guess on the subject; I have no inside contacts with the city. They might also be talking about a backup system controller associated with the planned system upgrade, possibly to be based at Frankford.