As part of the Q4 goals for Discovery I'll work with engineers and affected communities to communicate changes brought about by this work.
In relation to T158203, the index for Chinese will be upgraded to MB25 as the results of testing and user feedback has been positive.
A mention in Tech/News as it approaches deployment (when the change will appear to users) and a mention on discovery-l will come in time. I'll help with drafting/editing.
If we have time a post to https://zh.wikipedia.org/wiki/Wikipedia:互助客栈/技术 with a summary of improvements might happen. :)
To further the support this goal we're asking for some feedback on a potential update to the Japanese language analyzer. Message to be shared soon with the Japanese Wikipedia community.
Message and conversation has ensued on the Japanese Wikipedia.