Death of the Author is also about both intent and result. A catchy song about how fascism is cool is not the same as a fascist accidentally making anti-fascist arguments.
context also matters. Sure, I'm normally opposed to a song about how fascism is cool, but if it's from the OST of some Starship Troopers spinoff or a Warhammer 40k thing, I might be down for some satirical good times. You know, for the lulz of course.
Uh huh. That's why the Emperor keeps getting more awesome and right, just being held down by all his pesky traitorous generals and incompetent nobles, all their enemies actually do want to eradicate humanity, and the viewpoint character always sees some of the flaws in the system but don't you just know it, there's some Tyranids to fight!
GW has to say it's satire. They can't admit it stopped somewhere and became an earnest story, as all satire that goes on for too long tends to do, because admitting that means admitting they make piles of cash from a fascist property.
Like, for real, bro. The "Hope" of the Imperium was the return of Roboute Guilliman, a Roman coded god-king.