/etc/passwd in setup-2.4.15-1 has /sbin/nologin as news' shell. This causes the inn package to stop working. Either the /sbin/nologin needs to go away, or the inn package needs to be modified to remove it when inn is installed.
The inn user needs /bin/bash, or just something that exists?
Before the new version of the "setup" package, the "news" user had no shell at all, i.e., its line in /etc/passwd ended with "/var/spool/news:". I reverted to this when I discovered the problem with having /sbin/nologin there, and that seems to work. So I don't think it needs to have an actual shell -- it just needs to not have "/sbin/nologin".
Fixed in 2.5.1-1.