Upstream-Contact shouldn't be used to determine Author

I don't think it makes sense to use this field in determining the author of a package. DEP-5 explains this field as following:

Line-based list: the preferred address(es) to reach the upstream project.

In my understanding, this is someone who is the current active maintainer (or maybe a group of maintainers) of the project. The name of the field itself kind of implies that. In some cases, the original author isn't even active anymore, yet the project is alive and has active maintainers users can contact. Presenting such persons or a group as author(s) is misleading and potentially troublesome.