On the Autobot side, Bumblebee, Ratchet, Wheeljack, Blaster, Perceptor, and the Dinobots would survive, and be it in the shuttle attack, the battle of Autobot City, or in the fight against Unicron, every other Season 1 and 2 character would bite it, with Bumblebee surviving by being too small a target, Ratchet and Wheeljack simply being in the repair bay away from the battle, and the others being with Hot Rod's team. I'd also have Magnus drawn and quartered like the original script, and Devastator would stomp some of the Season 2 Autobot cars. Optimus Prime and Jazz would be rendered in stasis lock for years, and when they did come back, it would coincide with Prime's Powermaster upgrade and Jazz's Pretender upgrade and both would be somewhat traumatized by the experience. I'd have there be an episode where Bumblebee, being the youngest Season 1 survivor (who wasn't built on Earth), struggles to deal with the deaths of almost all his friends from the Ark, and maybe emerges a little grimmer and more serious, culminating in him trying to leave behind his old identity after becoming Goldbug. If there'd been more of a Season 4 and he got his Pretender upgrade, he'd grow to accept his mistakes and his past self, and become more at ease with himself. Ratchet and Wheeljack would take on a mentor role to him, trying to help him cope with the loss of Optimus, Ironhide, and the others. On the Decepticon side, I would have Starscream survive being blasted by Galvatron, but he gets launched into space to float for all eternity, as an act of revenge on Galvatron's part. He'd of course get discovered by the Autobots and repaired, and go through a character arc of struggling to fit in with a team that has different values than him, and the fact that the Decepticons don't want or need him anymore. I'd have it more clear who the Season 1 Seekers and Insecticons are reformatted into, with character moments earlier in the film that lead to them accepting and embracing their new identities as Cyclonus, Scourge, and the Sweeps. In terms of actual deaths, the conehead Seekers, Reflector, Laserbeak, Buzzsaw, Rumble, and Frenzy would fall. Perhaps in the same episode that Bumblebee would struggle to deal with the loss of his friends, Soundwave too would be struggling to come to terms with most of his cassettes dying, and he and Bumblebee would fight and eventually come to an understanding. Shockwave would survive the Movie, but he would be less trustful of Galvatron, culminating in a vicious battle where Shockwave ultimately dies at Galvatron's hands.