chpass appears to be aimed at updating "user database information"
stored in either YP/NIS (it's manpage should be updated to say NIS) or
/etc/passwd.  At one point, its code checks NIS, then has a comment
saying that since the user wasn't found in NIS, check the local
database, and then it promptly calls getpwnam().  For quite sometime,
NetBSD has supported the remote storage of "user database information"
in the form of Hesiod.  With the advent of dynamic nsswitch support,
"user database information" could quite literally be stored anywhere.
What do we want to do about the grossly out of date assumption that
getpwnam() only looks in /etc/passwd and NIS?