Technically, it's just an old (released in 2017-01-02) version bump.
Yet, if only it was that simple...
One thing is the build system change from autoconf to cmake.
Yet much bigger problem is that in the about two months after that release, various fixes were made in the repo (while it can still be downloaded from sourceforge, the main repo now seems to be github), some of them being *build*
fixes. Irregardless, no bugfix release had been made.
On the other hand, this version switched to lcms2, so it could be now restored.