Given that the development of the actual Collada format is “dead” for all practical purposes, I’d expect that “maintenance” of the library would more or less be 1) fix any serious bugs or security issues uncovered in the library itself, 2) update 3rd party deps that the library itself embeds/uses, 3) make it build with current compilers / C++ standards.
If that is needed, I can “volunteer” to do the maintenance. With the usual caveats, like I already managed to introduce a collada bug in 4.2.0 while cleaning up 3rd party dependencies (fixed in 4.2.1, but required platform maintainers to rebuild the lib). It would actually be easier if the library itself was vendored under extern directly within blender.