"People can complain about Corrin's personality and Fates' plot all they like, but Corrin is still a silver backflipping manakete princess who carries a luminous golden chainsaw and can turn her hands into the jaws of a mighty dragon to fire plasma blasts, and I want that in my Smash games damn it" ~Some guy on this other site.
Roberts has consistently shown some talent walking on this tightrope, so I think it'll be fine. Plus, it doesn't necessarily show that Megatron was justified at all; his original intent is what we agree with - not what he became after his killing of the Senate. The Decepticons were at some point a force for good and justified in most of what they did, but there's a point they should have stopped. Instead, they escalated.