As far as I know, attribution rights are unalienable at least in my jurisdiction. What that means in practice in larger software projects is unclear, but removing attribution for some people while keeping it for others would be against the spirit of the law.

There were no indent in removing or altering the history. Just a project that evolves over time, files are renamed, splitted, etc, and the list of copyright at the beginning of the file is no more relevant. The real truth is inside the git history, sadly part of this truth has been lost by the origian import, and even myself, the current maintainer, does not know it !