Last free update is 09.2, there were 3 more updates along the way with a bunch of content in them, i believe i don't have to explain how math works.
Except your math is wrong.
Release 9.2 first came out for the Supporters in May 2022, and was released for free in November 2022. The public releases are supposed to be behind the Supporter Versions by 3 Updates (having 2 months Development time between each update) so people that support the Project have a reason to do that (And dont even start claiming that its a Scam because of that, full time development of a game is not free).
So since the public release of 9.2 there was only one Update that was released, that being the Supporter only release of Version 13 that got released this month.
This means that Release 10.2 (released for Supporters in July of 2022) would be the next that is scheduled for release this month.
As for the reason for why there is no free release of 10.2 at this time I dont know. Might be that the Dev is on Vacation, might be that people fucked around in the Thread and now we all have to find out. The only one that knows the answer is the Dev.