I maintain it for Fedora, and would be happy to handle it in Debian; it's a dependency for one of my other packages (notcurses). Happy to enter into a team maintainership as well.
Hi Nick and Michael, I'd be happy to join this hypothetical team as well. I already maintain multiple C++/CMake packages, and I'm looking into using libdeflate in Pistache, a library which I maintain both upstream and in Debian.
Bye!