Yawn. Not really, only your fantasy world where you think the F-35's EW system is sub-par.
Possibly, except for radar range of course, but then there are still F-15s in service and the EX package adds to their capability.
So you're saying BAE made an inferior EW suite for the F-15 compared to the F-35? Yeah, dude, makes sense.
How about the F-15EX creates problems somewhere in their defence network while the F-35 quietly goes in and destroys stuff. Or the F-15EX creates the noise, leaving the F-35 passive. Complimentary/complimentary.
Er... That's exactly what the F-35 hopes to avoid, aka, alerting the enemy of your presence before SEAD/DEAD. This is something even Hostage mentions. The entire plan is to go in undetected, kill and run away before the enemy can react. The F-15 informing the enemy of intent is not complementary unless stealth doesn't work against the threat. But if stealth doesn't work against the target, then you have the F-15's and F-35's EW suites complementing each other, one working actively with additional capabilities, the other working passively because it lacks some of those active features.