As far as I can tell, they didn’t stop it - outdoor advertising is still banned there. It was hard finding recent online information about it though. The most recent references I found were a two-year-old discussion on Hacker News and a 2022 article from the BBC which mentions São Paulo’s ban and says that Grenoble in France has something similar.
I was puzzled by this too, so I took one for the team and clicked the link. Yes it does appear to mean that there were less users using the Chinese language in this survey than the one for the previous month, which implies fewer Chinese users: “Last month we saw quite a sharp drop for the Linux stats, which coincided with Simplified Chinese once again rising as the language choice on Steam. This is something that happens now and then.”
Why there is a link between Chinese users and Windows is an interesting question. Could be related to a higher number of Internet cafés there - not sure if that’s still true but it used to be - and/or greater acceptability and availability of pirated software in China compared to Europe and USA causing reduced demand for free alternatives.
that’s interesting that you mention that - never been there myself or anything, but I did come across reports that the city authorities had relaxed rules on large murals to make up for the lack of advertising, and there’s certainly a lot of pictures of some pretty impressive artworks!