Predacons Rising had the weirdest scene. Shockwave was overwhelmed by zombie Predacons, and implied to be dead, but then he randomly pops up for a few seconds and says something, then disappears again. He's not even seen during, or after the final battle. Was this an editing error? Maybe Hasbro insisted that they include a scene of him alive because they didn't want to kill off his character? Some people have suggested that he's a ghost? Was something cut?
I always wondered that myself, but I do not think he is a ghost. My assumption is he was able to get out of it, or Unicron just commanded his army to destroy Cybertron's core, leaving Shockwave alone. In the scene where the Predicons are fighting each other is the last time he appears. He tells them they are useful elsewhere and you can clearly see he has taking a beating (well if you constitute missing a wing a beating). Another logical assumption is he is pretty large and could probably sustain some heavy damage. The Autobots thought they offed him during TFP, and he managed to get out of that too. It did bother me how he doesn't return after that scene in the movie though, so maybe the creators forgot or they were pressed for time. My guess is Shockwave just went back to one of his labs to do what he does best.
Yeah, that works. As for the real-life reason, I'm guessing that Hasbro wanted to leave him alive for future shows.
Hasbro probably vetoed Shockwave's death in Predacons Rising and threw him in as the guy who convinced Predaking to fight with the Autobots. Shockwave should have appeared with the Predacons at the end when they beat the crap out of Starscream.
Shockwave doesn't seem like the type for revenge, it would be illogical for him, or that's how I perceive his character anyways. If I remember correctly in TFP he mentions to someone (I forget who) about how pointless it was for revenge or something of that nature, but if they wanted to indulge in it he wasn't going to stop them. I am sure that's the plan, maybe they will bring him back in RID, but you never know.
Shockwave had better things to do with his time than mess around with stupid zombie robots or illogical chaos gods. You think he gives a crap about a horrific zombie dragon apocalypse? No way, he's got too much science to work on without being distracted by such silly unscientific morons.
The only time he was all for vengeance was when he realized Starscream tried to get him killed, but he got talked out of it when he saw the good that came of it. In the finale when Starscream was ready to try to avenge Megatron then and there, he actually dragged off Starscream to safety. It was simultaneously logical and illogical. Illogical because Starscream hates him and tried to kill him, but logical since they'd just lost Megatron, they couldn't afford to lose anyone else. I found it amusing that Shockwave and Scream were on better terms in Predacons Rising, even if Scream couldn't help but condescend him as usual. Kinda like in AOE when the Autobots couldn't get along, but they had to since they were all that was left.