There’s a problem there, though. The propaganda was basically various versions of “The government (when run by Democrats) is bad, don’t trust the government.”
If they put up a notice saying, “This domain was seized, here’s the real facts!” the target of the propaganda isn’t going to buy it for a hot minute.
If they put up replacement content that doesn’t mention the government seizure, tha target of the propaganda is already primed to shout, “Fake news!” at anything that disputes their existing worldview.
It’s best to just let those domains return like a 504 Internal Server Error and die a quiet death.