If anybody comes WVR with the F35, why waste a missile, when you simple can take the gun and your superior maneuverability to shoot it down? Besides, DIRCM, just as the active EM decoys will soon be added to all state of the art EW systems.
As said, modern EW systems are similar in content of sensors or use of them, it's just the performance that might differ. For both, the EW won't be just a defensiv aid anymore, but increases the situational awareness far more than in older fighters, that were dependent on the radar only. The stealth advantage of the F35 might make it even more useful, because it can stay undetected for longer, even if both fighters are just using passive sensors.