As we all know, in the episode "Megatron's Master Plan" The Decepticons trick the people of Earth that the Autobots are evil, and Earth exiles them. Then the Con's take over. Among the enslaved humans are the Witwickys and Chase. While I know they could not do this because it is a cartoon for kids, but, in universe, why didn't they execute any known human allies of the Autobots? You would think that after taking over the planet, the first thing Megatron would want to do is reduce any change of resistance, which would include removing anyone who worked with the Autobots.