Earlier quoted context omitted.
In what sense aren't police labor? "Labor" literally just means "work"? It's not like the unions of managers, pilots, lawyers, NHL players or software developers aren't "labor unions"? Policemen are employed so their organization as employees is a labor union (or just "union" for short)?
Police are what shows up when labor strikes. They’re part of the government, not a part of the collective “labor” that is the rest of the working world. As an example, police are part of an association but not a union. They aren’t legally allowed to strike anywhere in the US. They serve the interests of capitalism, which is the other side of the coin of workers’ rights
Some restrictions on strikes usually covers lots of different jobs (e.g. nurses).