Interesting video. Never saw that although I know many of the people in it.
Anyway...
As for the license, look at the frequencies. They are all the NPSPAC Interop channels. I don't know why they licensed them as TRBO (and they are), but they are also licensed as SNFM which is the mode used in literally every radio on the system. There is no MotoTRBO used on the system at all. Aside from those analog channels, everything else is P25 (Phase I). In addition, the system has expanded in the past couple years into the 4-county (and growing) system called ICORRS. Look it up on the database. You will see it's all P25.
BTW, all the interop channels are also simplex, not repeated.
In the video, those users using digital radios were all P25 radios (XTS1500s, XTS2500s, or XTL2500s). There were some HT600s and P200s shown as well. Those are likely for the services that were using VHF. Some STILL ARE using VHF, but of course not those models anymore. There is also one municipality using 800 MHz P25 conventional.
So, while the county legally could use MotoTRBO, they are not, never have, and the radios in use do not have that capability.
I will add that there is one public works that is using MotoTRBO, and another using NexEdge, but that's unrelated to any county systems.