it seems very likely that the timing was purely coincidental. It’s more likely that AO3 became a target of China’s ongoing attempts to suppress queer and explicit media content, as a part of its larger dedicated pattern of internet censorship.

Chinese censors have been preparing for new, tighter restrictions on the type of content considered acceptable to post online In January, the Chinese government announced that beginning March 1, it would be enacting new regulations against content on Chinese websites. The new rules include restrictions on “negative” content. This is likely part of China’s ongoing effort to curtail internet discussion about the months-long Hong Kong protests (which call for a return to the region’s former democratic government) and many other aspects of its restrictive government. The regulations also aim to hold specific websites accountable for the content posted on them.

According to Variety, the new laws place the onus on individual websites to ensure that the content posted on them is primarily positive, uplifting, and devoid of misinformation. A nebulous list of unacceptable content includes content that “harms the nation’s honor and interests,” and any type of “sexual innuendo ... sex, gore or horror,” and anything that could potentially “violate social mores.”

These are extremely broad terms which appear to push websites that operate in China toward more zealous self-censorship. It’s possible that the Archive of Our Own, which has always been strident about not censoring content, became one of the first casualties under the new law.

From the article

It doesn't look good. But this is the kinda surface-level reporting that doesn't really get at the heart of the issue. Are they censoring gay scenes, or pedophilic or abusive power-relationship dynamics amongst gay individuals. Would a Call By Your Name (controversial, large age differential, seen somewhat predatory even by the queer individuals I know) get censored. What about Portrait of a Lady on Fire, slow-burn, yearning, and romance amongst equals, Would that also be censored?

I know Archive of Our Own has a lot of queer content that is decidedly wholesome and beneficial for teens and young adults wanting to find representation and grow into their identity; but the problem is in their attitude "strident about not censoring content" which also allows for reactionary, disgusting, vile, and problematic content to be distributed amongst the community.

From a The Verge article, after doing some cursory googling:

But fans have also long disagreed about what content any given space should host. Some early archives banned specific subjects, while others put restrictions on certain characters or relationships. AO3’s free speech maximalist approach to fictional content was founded in direct response to corporate censorship as a way to ensure that all fanworks were protected on the basis of simply being fanworks, rather than meeting a standard of literary merit or adhering to thematic guidelines or restrictions.

“One of our most quoted sections from the ToS is: ‘You understand that using the Archive may expose you to material that is offensive, triggering, erroneous, sexually explicit, indecent, blasphemous, objectionable, grammatically incorrect, or badly spelled,’” Matty Bowers, AO3’s policy and abuse chair, tells The Verge.

Recently, the loudest opposition to AO3’s “maximum inclusiveness” has centered on sexual acts that are often considered taboo or are illegal, like whether writers should be allowed to depict things like rape, incest, statutory rape, or pedophilia, regardless of whether the stories are marked with clear warnings.

Thornier still, some fans want AO3 to police the way these sensitive topics are depicted, including whether sexy depictions of unhealthy relationships encourage real-world abuse or the difference between a depiction of rape and writing a “rape fantasy.” The conversations echo everything from 20th century obscenity trials, the feminist porn wars of the 1980s, and the long-standing debates within fandom itself.

I don't think free speech should cover things like rape, statutory rape, and pedophilia. I don't think certain topics are or should be allowed to exist within the protection of free speech or corporate endorsement (your refusal to ban or delete bad topics is in itself a tacit endorsement).

This website has a deliberately hostile approach to "free speech". It has made us grow pretty slowly, and even turned some people off, but it's also one of the least reactionary places I have seen on the fucking web.

I think Vox is using the problems these laws are causing to LGBTQ minorities to ignore the larger problems posed by immoral and problematic content that Chinese censors might be actively seeking to prevent from entering the web.

Facebook human moderators get PTSD and suicidal ideations from the amount of horrific content that gets uploaded to the site. Americans also enjoy 3.2 million man-hours of active moderation to prevent and reduce the chances you run into some really horrific shit using one of their sites. Meanwhile, in the Global South, Fb and Instagram are being used to traffic and rape women. They are used to recruit young boys and teenagers into cartel hitmen training camps. Instagram has been found to give young girls Eating Disorders and suicidal ideations as well (per the latest WSJ article about FB inside data).

Maybe the idea of an uncensored internet is not a wholly "GOOD" concept. And it should be treated more critically than what bourgeois media, tells you to think it as.