I posted an MR recently that would help address the issue with libnss-db. The proposed MR creates a db5.3-free `libc6-libnss-db` package as part of glibc that provides the `libnss-db.so.2` and is a direct functional replacement for the stand-alone libnss-db. It would allow as seamless as possible a transition between the two, and uses existing code in glibc that is both db5.3-free and actively maintained upstream.
https://salsa.debian.org/glibc-team/glibc/-/merge_requests/38 I also opened bug #1132249 to discuss
