Sounds legitimate. Dreadwing's death killed me inside, and then I drew the conclusion that it was all Starscream's fault. If he hadn't tried to revive Skyquake using the dark energon way back in the beginning of the series, my falcon wouldn't have attempted to kill him. And Megatron wouldn't have shot the one thing that could have saved so much effort in taking over the Omega Lock through the chest. Also, Starscream shouldn't have known about the parallel dimensional plane Skyquake got stuck in. But he did. Which is crap.
You could also argue that if Dreadwing hadn't stopped Knockout from trapping Megatron in Starscream's mind, Dreadwing would still be alive, Starscream (and therefore Megatron) would be dead via Dreadwing, and Optimus Prime would have been free to revitalize Cybertron to the joy of millions. So essentially, Knockout's little moment of treachery could have saved the universe.
The thing different I see with that is if Knock Out had pulled the plug, trapping Megatron in Starscream's mind, everyone would have known. Either with Starscream being the screeching thing he is, Megatron channeling through to express his rage, or other logical reactions two hellbent rivals might do when finding they have been stuck in one head. Everyone would have known almost instantly with the commotion it would have caused, Knock Out would probably have been executed if it weren't for the fact they needed his talents as medic to reverse the operation (which I can't see him complying with immediately because once finished he would still be punished severely if not offed), and Dreadwing more than likely wouldn't have even seen the memory of his brother being turned zombie. Assuming you're saying he still came into the room at all.
The cut off from the patch, from what I understand, is in no way a smooth process and would have alerted both the patients to what had happened, successfully diverting focus on the flashbacks. And then with that spawn of events, the Forge of Solus Prime wouldn't have been handed over to the Autobots so they would have no way of quickly creating a spacebridge, if the Decepticons had still figured out what the Keys were for they would have departed (likely with some delay) and reconstructed Cybertron (maybe even cyberforming Earth if Megatron still had any influence in the situation over that concept), and Dreadwing would still be alive.
In my opinions at least. Many things could have happened that didn't.