In the 20th century DARPA might be right. But two decades into the 21st century? It sounds pointless.
It is one thing to somehow get any news agency who even tries to be reputable to sign their stories, the government to sign their official publications, and people to expect anything claiming to be them to actually prove it.
Allowing anyone the authority to enforce "blocking misinformation" for "national security" is a concept tailor made for a use. My Lai and Tiananmen Square would be "misinformation" while antivaxxer bullshit and "if you vote with a relative in jail you will be arrested" style misinformation would go untouched because it would be born an instrument to be abused for power.