It's realistic. Most law enforcement officers only have a high-school diploma. It isn't unreasonable to think that they would think that "Eliminate the State" was some kind of anti-american anarchic slogan, or that "Hash" was referring to concentrated marijuana...
Cops are a pretty stupid bunch. Not all of them, but quite unfortunately the majority of them...
Maybe they were thinking (light heartedly) that a practical post-quantum signature scheme might raise the attention of the government again. So they're giving a shout-out to the legions of governments officials that might find themselves on that page once they whip themselves into a panicked frenzy.
The page has an anarchist-style logo in the upper left. I suspect that this, in addition to the normal stereotyping of "the authorities" as being clueless with regard to technology, is what led to the jibe.
It's a pun, but that's all. The plain reading of 'We are not talking about eliminating other types of states. We love most states, especially yours! Also, "hash" is another technical term and has nothing to do with cannabis.' does not indicate a serious commitment to anarchism.
Daniel J. Bernstein, who is hosting the page, doesn't seem to be public about his politics, but is probably not an anarchist. Since it's associated with several universities, it is probably just a bit of CYA combined with tongue-in-cheek.
Cops are a pretty stupid bunch. Not all of them, but quite unfortunately the majority of them...