This definitely sounds like a bug to me. Assuming your company is maintaining 3rd-party repos for both the older and newer versions of the distro, doing a dist

This definitely sounds like a bug to me. Assuming your company is maintaining 3rd-party repos for both the older and newer versions of the distro, doing a distro upgrade should, logically, switch to your repo for the newer OS version automatically, so it's completely seamless to the user. If the distro isn't doing that, that seems like an oversight.