I asked the question to a FN rep during a state presentation and didn't get an answer other than "you have a black SIM, you have priority".
Scenario: large event in area with low density coverage. Think, 30 miles outside a city and a large farm/park where a music festival is held yearly and expected (non-COVID) turnout anywhere from 60,000 to 100,000 people. all with cellphones. All streaming and uploading and tweeting every fart they let out.
FN uses shared spectrum. Band 14 is "opened up" to Joe Consumer. So how does the serving site/sector determine my device has priority over the thousands of RF generating consumer devices all spewing forth on those few available site/sectors? Explain this to me. I'm an LMR radio guy who knows enough to know that if 50,000 phones are all on affiliating/sending data to that serving site, it's going to bottleneck. Sure, once you get to the FN core, you're prioritized, but you can't do that if the onramp and offramps to that highway are full of cars.
Oh, and that event I mentioned? Worked it two years in a row and that is exactly what went down. Except Verizon for some reason didn't have any issues.