It's not just mistranslation of the phrase; the tweet deliberately excises context surrounding it, seemingly to imply that the CPC is trying to do some sort of crude artistic censorship, as if Xi is trying to prevent the Chinese from watching superhero slop movies, playing gacha games, or reading Ulysses because James Joyce included too many fart jokes in it, that it's some sort of socialist-flavoured puritanical mass thought control project, rather than doing pragmatic and measured anti-corruption/anti-graft stuff among the elite to avoid inciting mass political dissatisfaction.
In full, Article 150 reads: "生活奢靡、铺张浪费、贪图享乐、追求低级趣味,造成不良影响的,给予警告或者严重警告处分;情节严重的,给予撤销党内职务处分。", i.e., "Those who lead extravagant lives, waste money, pursue pleasure, and pursue vulgar interests, causing adverse effects, shall be given a warning or a serious warning; if the circumstances are serious, they shall be given a disciplinary sanction of removal from their party posts." Based on the way the regulation is phrased, it's clear that the core idea behind it is essentially that the personal lives of party officials shouldn't cause detriment (造成不良影响) to the people and the Party by being wasteful or manifestly corrupt. It's the consequence that's the key ingredient, the wasteful and crude behaviours in of themselves are just the typical methods by which those bad consequence are arrived at. It's not merely enjoying kitsch hobbies that fall outside reading theory and volunteering at the local soup kitchen (btw, do they even have those in China? What's the homeless situation there? Is it a problem in the big cities? Is the CPC doing anything about it?) or spending money on stupid expensive things for personal enjoyment, but when that enjoyment is pursued to such an egregious extent/in such a way that causes material or measurable harm. A guideline published by the Guangdong Provincial Disciplinary Inspection Commission supports this interpretation, saying that "violation of this [Article 150] disciplinary regulation is based on "causing adverse effects" as a constituent element. On the one hand, the adverse effects should be comprehensively grasped from the living standards, consumption standards, customs and habits of the local people. On the other hand, it depends on whether it affects the masses' recognition of party members' practice of the core socialist values. If their extravagant life and other behaviors do not cause concentrated reflections from the masses, or the circumstances are minor and do not cause negative comments, and do not affect the masses' recognition of party members and cadres' practice of the core socialist values, it is generally not appropriate to identify them as violations of discipline.". If I read all this correctly, it's essentially just a rule against party members being involved in big flashy corruption scandals. You know, the ones that regular working folk don't like, and that the US and the West likes to point out to lecture about how communism is actually authoritarian and doomed to fail.
If you're interested, you can search online to see what weirdly specific examples/precedent cases the published guidelines cite in explaining what constitutes an offence, including a provincial party secretary being widely known to regularly (i.e., more than twice a month) drink expensive wine and dine on exotic endanged animals in high-end nighclubs (entirely on the nighclub owner's expense, and in a nighclub deliberately designed by political flunkies to fit said party official's tastes), or "spending several months' salary to buy milk, scanning the QR code in the milk bottle cap to vote for an entertainment idol, and then pouring out the whole box of milk, arousing strong public condemnation". Wild stuff.
Hmm, the person tweeting this (as far as I can tell, they're not living in China currently, and is some 1st gen Chinese Canadian YA author who writes Chinese history-inspired fantasy/SF) provided some "elaboration" on the alleged situation:-
Not sure about the anonymous "Chinese lawyer" source that they're relying on, and I can't find a news source reporting on this case; elsewhere in the thread they posted an SCMP article, but it was about a "coventional" heterosexual jody case from earlier this year). Be that as it may, on first glance, the purpoted legal logic doesn't seem to be completely without legs to me? If cohabitation is legally defined as "living as if husband and wife", it seems at least arguable (not saying that it's an argument that Chinese courts will definitely accept) that the court cannot legally recognise a "lesbian cohabitation" situation without first recognising the concept of a marriage/legally-recognised union between two women?