This sounds like more like a usability issue than a bug. The reason you see those messages is that update-manager will put back ubuntu-desktop during the ugprade. When you run do-release-upgrade it will not do that, it runs in "server" upgrade mode by default.
Thanks for your bugreport.
This sounds like more like a usability issue than a bug. The reason you see those messages is that update-manager will put back ubuntu-desktop during the ugprade. When you run do-release-upgrade it will not do that, it runs in "server" upgrade mode by default.