What you see in sentinel is going to be exactly what you see in the database, and what is in the database only gets updated if scanner listeners submit updated information. The NXDN system, even if no longer used (not saying that it necessarily is though), will appear in sentinel indefinitely until the system is confirmed to be decommissioned and an update is submitted to have the system removed (deprecated) from the DB. Do be aware that just because a DB page or site has not been updated in a while does not mean the data is necessarily inaccurate as systems/sites can operate for years with minimal to no changes.
Your best bet is to listen to both the NXDN system and VIPER to see which is currently being used. The last time I was over there (years ago), Lee county had conventional traffic patched to the NXDN system. I distinctly recall hearing Lee County EMS on NXDN, but I cannot remember what, if any, VIPER usage I noted at the time.
The article you linked seems to indicate that, at the time the article was written, Lee County was using a system other than VIPER that was unsatisfactory. I found a thread from 2022 that stated they were still using a mix of NXDN and conventional at that time. It sounds like they have been considering a switch to VIPER, so that could be in the works or have already happened. Again, the best thing to do would be listen for yourself or ask in the NC subforum.