This story is worded strangely. It seems to indicate that an FBI informent wrote it, therefore the government wrote it. But several proud boys were FBI informents apparently.
It's typical GP. A rehash of old, unsourced or twisted claims. Flores claims an associate from the cryptocurrency world named Samuel Armes provided her with the document. He testified that he recognizes some of the content, but his document was nothing like the plan Flores posted on posted on Telegram.
Armes was at one point employed by the State Department. It's very possible he is still an asset, particularly being in the cryptocurrency world, which is heavily infested with extremists with limited national loyalties. Right wing, left wing, anarchists, communists, fascists, you name it. So, sure, he could be an asset. But you're not going to see GP make any effort to make that connection in any serious manner.