Repro: https://codesandbox.io/s/fast-water-4i4jb

Notice the flash. I'd expect `suspended` to be `true` during the high pri render.
return (
          <Suspense fallback={<Text text="Loading..." />}>
            <AsyncText text={page} ms={5000} />
          </Suspense>
        );
      }
      
      React.unstable_withSuspenseConfig(
        () => ReactNoop.render(<App page="A" />),
        SUSPENSE_CONFIG,
      );
      expect(Scheduler).toFlushAndYield(['Suspend! [A]', 'Loading...']);
      
      Scheduler.unstable_advanceTime(400);
      await advanceTimers(400);
      expect(ReactNoop.getChildren()).toEqual([span('Loading...')]);
      
      Scheduler.unstable_advanceTime(5000);
      await advanceTimers(5000);