What about a compromise? We don't print is by default with -w/--dump-debug, but only when explicitly requested?
Now that I know binutils readelf also support --debug-dump=.gdb_index I played a bit with it to check the output agrees. It does include the section in case of using -w, so we should keep that the same i we care about compatibility with binutils.
I we add this then I am willing to keep the format parsing up to date with whatever changes gdb makes. Since I am interested in making sure that the info is eventually also usable by other consumers (or help migrate gdb to other more standard indexes).
Cheers,
Mark