Comment 2 for bug 554621

Because the distributions field is per changelog *entry*, it would be my expectation that uploading a source package with multiple distros would, if ever implemented, be implemented to build it in the first-listed distro, and then publish the resultant binaries in all listed distros.

If the same source were to be built in multiple distros, some munging of the changelog would be required to change the versions. To represent this via the changelog distributions field alone would be impractical, unless a fixed convention was adopted for transforming the version string.