this one example underscores that "freedom" - having access to the source - is no longer the only factor, meaning that we are heavily and critically deependent on decisions made by distro maintainers.
Again, this has always been the case! Unless you're packaging things yourself, you're dependent on the distro maintainers (or sometimes the upstream developers) to package them for you, or you have to install them outside the package manager which carries its own set of risks.
The distro maintainers have to manage their (often limited and unpaid) time wisely. In Debian's case, choosing systemd as the init system means that package maintainers only have to write much shorter systemd service files instead of longer sysvinit-style startup scripts. As a developer, I can certainly understand that decision.
Perhaps software freedom alone is no longer enough, and in some cases I agree. But in this case, I don't think I can fault Debian (as a volunteer project) for not wanting to do work they don't have to.