I think 40k never was satire and is more of a parody. It's a silly set of rules to give you a narrative reason for why you're playing against your opponent. Prior to Warhammer, most wargames were historical. You were SOL if you want to play an American Civil War game, but you and your friends only had Union collections. By dipping into parodies of sci-fi, 40k gave you a reason to have Luke Skywalker from Hoth to fight Luke Skywalker from Endor.

Unfortunately, no matter how silly you make something, if reactionaries find their way into your space, they won't leave. Orks are a good example. In 2nd. Edition, they were parodies of Nazis. Obsession with wonder weapons, might makes right and so the strongest person should be in charge, magical thinking, etc. They had even had German uniforms. But then actual nazis showed up, thought the models were cool, and thus those models were discontinued. That didn't make the nazis leave, despite statements over orks were making fun of nazi tropes.

Because Brits are a bunch of libs, they didn't know how to get rid of fascists, so here we are. Games Workshop could completely stamp out nazis by banning fascists from events, issuing boycotts, etc. These milquetoast steps are still too radical ("muh laws of Spain!), so of course nothing gets done.