The fixes seem to work in my build chroots for all 4 releases:

evan@caron:~$ schroot -c oneiric-amd64 -u root
(oneiric-amd64)root@caron:~# apt-get update -qq
(oneiric-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(oneiric-amd64)root@caron:~# insserv &>/dev/null
(oneiric-amd64)root@caron:~# ls /etc/rc6.d
README         S01reboot    S01umountfs      S01umountroot
S01networking  S01sendsigs  S01umountnfs.sh  S02urandom
(oneiric-amd64)root@caron:~# echo 'deb http://localhost:9999/ubuntu oneiric-proposed main restricted universe multiverse' >>/etc/apt/sources.list 
(oneiric-amd64)root@caron:~# apt-get update -qq
(oneiric-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(oneiric-amd64)root@caron:~# ls /etc/rc6.d
README         S02urandom   S31umountnfs.sh  S60umountroot
S01networking  S20sendsigs  S40umountfs      S90reboot
(oneiric-amd64)root@caron:~# hash insserv
-bash: hash: insserv: not found

evan@caron:~$ schroot -c natty-amd64 -u root
(natty-amd64)root@caron:~# apt-get update -qq
(natty-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(natty-amd64)root@caron:~# insserv &>/dev/null
(natty-amd64)root@caron:~# ls /etc/rc6.d
README         S01reboot    S01umountfs      S01umountroot
S01networking  S01sendsigs  S01umountnfs.sh  S02urandom
(natty-amd64)root@caron:~# echo 'deb http://localhost:9999/ubuntu natty-proposed main restricted universe multiverse' >>/etc/apt/sources.list
(natty-amd64)root@caron:~# apt-get update -qq
(natty-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(natty-amd64)root@caron:~# ls /etc/rc6.d
README         S02urandom   S31umountnfs.sh  S60umountroot
S01networking  S20sendsigs  S40umountfs      S90reboot
(natty-amd64)root@caron:~# hash insserv
-bash: hash: insserv: not found
(natty-amd64)root@caron:~# logout

evan@caron:~$ schroot -c maverick-amd64 -u root
(maverick-amd64)root@caron:~# apt-get update -qq
(maverick-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(maverick-amd64)root@caron:~# insserv &>/dev/null
(maverick-amd64)root@caron:~# ls /etc/rc6.d
README         S01reboot    S01umountfs      S01umountroot
S01networking  S01sendsigs  S01umountnfs.sh  S02urandom
(maverick-amd64)root@caron:~# echo 'deb http://localhost:9999/ubuntu maverick-proposed main restricted universe multiverse' >>/etc/apt/sources.list
(maverick-amd64)root@caron:~# apt-get update -qq
(maverick-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(maverick-amd64)root@caron:~# ls /etc/rc6.d
README         S02urandom   S31umountnfs.sh  S60umountroot
S01networking  S20sendsigs  S40umountfs      S90reboot
(maverick-amd64)root@caron:~# hash insserv
-bash: hash: insserv: not found
(maverick-amd64)root@caron:~# logout

evan@caron:~$ schroot -c lucid-amd64 -u root
(lucid-amd64)root@caron:~# apt-get update -qq
(lucid-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(lucid-amd64)root@caron:~# insserv &>/dev/null
(lucid-amd64)root@caron:~# ls /etc/rc6.d
README         S01reboot    S01umountfs      S01umountroot
S01networking  S01sendsigs  S01umountnfs.sh  S02urandom
(lucid-amd64)root@caron:~# echo 'deb http://localhost:9999/ubuntu lucid-proposed main restricted universe multiverse' >>/etc/apt/sources.list
(lucid-amd64)root@caron:~# apt-get update -qq
(lucid-amd64)root@caron:~# apt-get dist-upgrade -yy &>/dev/null
(lucid-amd64)root@caron:~# ls /etc/rc6.d
README         S02urandom   S31umountnfs.sh  S60umountroot
S01networking  S20sendsigs  S40umountfs      S90reboot
(lucid-amd64)root@caron:~# hash insserv
-bash: hash: insserv: not found
(lucid-amd64)root@caron:~# logout