(original article in Swedish that reported this)
Posting this because I hadn't heard about it before and I'm probably not the only Mullvad user here, so might as well.
The party claims to stand for a "class-conscious populism" which according to party leader Markus Allard takes inspiration from marxist ideology and unites the "productive" classes of society against the "Transferiat", with the "Transferiat" being a term coined by Allard to describe the classes of society that lives off transfers that are a net negative for society such as those who, despite having an ability to work, live off social welfare benefits, as well as those who work "made-up services"[...]
The party differs from modern day left-wing parties by seeing the working class as co-dependent with people working in enterprise and business and instead sees the classes that "live off transfers", as specified, as a large economic net-negative and an obstacle for a functional society.
Their ideology is nonsense fake-marxist revisionism to redirect anger at capitalism and turn it against immigrants and people who need social welfare (though they do back some generally left oriented social policies, their main thing appears to be racism)
Even if you're comfortable with funding this, it still begs the question of just how trustworthy Mullvad actually is.
I guess this still beats any of the dozens of Israeli VPNs that definitely spy on you, but it's not great 
Hot take: Interesting but I don't care. You shouldn't buy a VPN for political reasons, if you go looking for super anarchist/Marxist VPN services you'll fall right into a fed honeypot.
The VPN space is very fucked. Mostly zionist intelligence cut-outs, suspicious parties like Proton that might be the CIA's new crypto-AG, and so on. I mean it is a prime place for intelligence and police honeypots and a high priority target for the eyes alliance. Real fish in a barrel the targets come to you situation with VPNs for western mass surveillance intelligence spying. There are unfortunately no good no-logs, full-featured, unlimited traffic VPNs headquartered in western-immune, western hostile countries like Russia or China. So your choices are suspicious, weird, genocide funding/known compromised all around. There are no perfect choices.
What there are, are choices that have passed a certain sniff test of not keeping logs that are accessible to the police (whether there are logs kept by the eyes alliance groups which cops will be told "fuck off" to is another question) and Mullvad for good or ill passes that test. Being able to mail them cash is really great and cops couldn't find anything. The fact they turned off port forwarding makes them unsuitable if your major use case is yo-ho or other types of torrent enabled file sharing but for privacy they're hardly the worst option IMO.
So stop dooming if you paid for a subscription. Continue to use it. Honestly feel safer swimming next to fascists in this sense because they target the left not fascists and hiding among them in this kind of a case seems like it has no downsides from a privacy perspective.
Your money isn't going to bring about fascism and you shouldn't feel guilty buying a service that happens to be run by someone who gives some profits to fascists. If you feel guilty over that then go live in a cave in the woods because spoiler: things you buy everyday including shopping at a supermarket, major electronics where both available brands do it, etc are all in on supporting fascism and you won't "discerning consumer" your way out of fascism. Your safety and finances take priority over this kind of feel-good purchasing behavior.
Further if you already paid don't stop using it. That's just giving them free money from your lack of use given you already paid.
Imagine if they had the laws good for that it'd be pretty dope