Oh sweet summer child. They've been doing this since 1986.
The first animated film alone got away with violently gunning down several major characters in the first 10 minutes! Including one barely offscreen shot of Megatron shooting Ironhide's head point blank. With the Fusion Cannon. One character is blasted so hard he's burnt into a charred crisp that crumbles to dust. Another explodes.
In the third season, Optimus shows up as a zombie whose body is horribly mangled onscreen.
Beast Wars had a character get stabbed in the heart, leading to him exploding. Then the character who did the stabbing's destroyed remains float to the surface. Another is hit by an explosion and has his charred head shown next episode.
Armada had Optimus crumble into dust in one episode. In Energon Hot Shot briefly loses an arm. In Prime, a character is stabbed to death in the first episode, has his corpse resurrected as a zombie, which is then dismembered.
And that's not going into the many many times someone was maimed in a way. Or the tamer deaths that they could never have done.
In short, Transformers has always gotten away with a lot of violence they'd never be able to get away with if the characters were human.