Comment 23 for bug 369575

> They may want to, but I don't think the added complexity of debconf solely for what I believe is a rarely-used option makes sense. [...] I don't think debconf offers much benefit here.

Fair enough, though I hope you're not suggesting direct modification of the /etc/pam.d/common-* files as a practical way of doing site customization. (That'll work fine until the next time someone wants to run pam-auth-update...)