sources.list not fully upgraded

This is a very little question. Is my sources.list file out of whack?

I upgraded 17.10 on top of 17.04, on top of 16.10, etc. Today I notice some quirky things in my sources.list file. The deb-src lines seem to all be incorrect:

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://us.archive.ubuntu.com/ubuntu/ artful universe
deb-src http://us.archive.ubuntu.com/ubuntu/ xenial-updates universe

Note I'm on artful for deb but deb-src is historic. Furthermore, the repositories differ, one release, otherupdates.

More toward the end:

deb-src http://security.ubuntu.com/ubuntu xenial-security universe
deb-src http://security.ubuntu.com/ubuntu xenial-security multiverse
deb http://us.archive.ubuntu.com/ubuntu/ artful-backports restricted universe multiverse
deb http://us.archive.ubuntu.com/ubuntu/ artful-updates universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ artful-security universe restricted multiverse

I'll manually update those. I'm guessing that a glitch happened in the transition out from xenial and it has the updates for y and z flummoxed.

I'm mostly writing this to warn others that there can be mis-matches due to repeated upgrades and that the source package repository can fall out of sync. So if you run "apt-get source xxx" it may be you pull the old/wrong version of something. It is worth a few minutes to inspect /etc/apt/sources.list and the files in /etc/apt/sources.list.d