I think ksh was the first shell I was exposed to vi command-line editing in on a Sun workstation a long time ago -- I haven't thought about it in years as it seems bash is so prevalent, but good to so some folks still keeping it alive.
At work, in the scope of a migration from RHEL 6 to rhEL 7, I have spend a lot of time migrating scripts from ksh (pdksh) to bash in order to remove this dependency. I have not seen any advantage of ksh over bash. There are many differences (ksh is less strict), but IMO there is no point in keeping 2 mostly similar but incompatible shells when less and less people are using shell. I think ksh should die. Maybe I am missing something ?
There's basically nothing to see here. One or two minor bug fixes, a few cleanups, and a new build system replacing one that already worked fine.
In my experience replacing the build system and doing nothing else is usually a good indicator for a project that will be soon abandoned. If that's the first priority it means there's no real drive to implement anything new.