In World War II kind of negate the entire need for and purpose of Sector Seven? Wouldn't defense secretary Keller have known that sentient alien robots were on Earth and had helped in the past?
this is what happens when you are constantly getting new writers who apparently didnt see or care about the events of previous films
With all the Transformers related things being kept secret whether it be the Allspark's and Megatron's existence, the Ark on the moon, the Seekers, maybe this is just another one of those things. Maybe Bumblebee and Hot Rod were part of a secret team.
I hate to defend the clusterfuck this series has become, but wasn't Sector 7 simply monitoring alien activity on Earth?
Germans: "Un dere gigantic robots!" Allies: "They're out of their minds, boys. Death by firing squad!"
They were working with the Order of Witwicky a British origin secret society. The UK knew that doesn't mean they'd tell the US exactly.