Asynchronous Events Interrupted?

Code:

public class TestPlugin extends JavaPlugin implements Listener {
 
  @Override
  public void onEnable() {
    super.getServer().getPluginManager().registerEvents(this, this);
  }
 
  @EventHandler
  public void onPlayerChat(AsyncPlayerChatEvent event) {
    System.out.println(Thread.currentThread().isInterrupted()); // outputs true;
  }
 
}

Why is the thread interrupted? More of, how?