I'd say that it doesn't have chaff/flares because it is never meant to get into contact with AA defenses (yea, I know, a guy shot it down...) and it doesn't need a jammer because it would only give away the location of the a/c.
Think of the B-2, do you think it has a jammer/defensive stores? It doesn't.
The airspace in which it gets deployed will be clear of AA threats.