There isn’t enough people to keep the English(US) Style Guides and the website in general up to date. It is a small team doing a LOT of work. It would become a huge challenge to just keep all the different translated versions of the Style Guide in sync with each other.
Translations are hit and miss even in the common European languages. There is a surprising number of partially started, never updated work in the translations. I joined the Transifex group to translate Picard to English (British)(Canada)(Aussie). Trivial stuff I know, but it did mean getting to see the translating from the inside.
I can see a situation where someone in the USA points at a style guide, then a French, Dutch and Japanese reader attempts to read the same sections in their native languages. Getting totally different text due to them being out of date. And the more obscure a language gets, the harder the updates will be.
It also makes it harder to update the original USA Style Guide text as any time it is changed it means all the other languages get into an unknown state.
What surprised me the most about the Transifex site is the lack of community in there. No obvious way to talk to other editors. I also expected to get the odd email notification when new text is to be translated.
These are not criticisms - I am just trying to show there is a lot missing even for common languages. Resources and labour are always in short supply. The team already do a lot with very little resources.