Haven't heard of this regency plot or regency mechanics good on you though since regents in china would have puppet emperors. Is their a new version?
We don't have any special regency mechanics in China, and as things currently stand there aren't any plans to add any such mechanics in China for a number of reasons I brought up recently (and even if we decided differently it'd not be something that'd we'd do anytime soon). We do, however, have such mechanics in Japan, since regents were kind of a big deal there.
As for a new version, the most recent proper release was in September. There was a "new release" roughly a week ago, but it accidentally contained a bunch of things it should not (WIP content missing huge chunks, at least one internal "experiment" that might never lead anywhere that's not properly contained, several known bugs introduced during development, etc.).
Given that it'd be a significant amount of work and testing to get that version into something that could be released (even using a "Cut everything WIP" approach rather than a "Finish everything WIP" approach) and that it'd not be a significant improvement on the last proper release (and would lack fixes for some bugs discovered in that version that should be possible to fix) I'm of the opinion that a rushed "update" is a worse idea than re-releasing the most recent proper version with a shiny new version number and then doing a proper update in the future that's both more extensive and more polished, and unless LumberKing tells me otherwise that means a release won't be rushed.