First thing I check under such circumstances is whether I actually need/run that service at all. If I can disable the service, I need not worry about its configuration file(s) and make sure that the new one is active and the old one is put aside.
Then, if I cannot judge the changes by looking at the files themselves, I look at the manual pages or other documentation of the service. If in question what the service/package actually is, "rpm -qf <configfilenameincludingpath>" ought to tell you which package "hosts" the config file (*not* the "rpmsave" or "rpmnew" file, but the actual config file name). If the man page doesn't help (or doesn't exist), then "rpm -ql <packagename>" may expose some documentation files installed on the local system and "rpm -qi <packagename>" sometimes gives a pointer to some project web site.
If you feel that the package installer needs to report more and/or better details on the upgrade process, you need to contact the package maintainer, which usually is someone "upstream" from SUSE for open source packages. Of course, opening a service request with SUSE will make sure you receive appropriate installation/upgrade support, too.