What that part of the GPL does absolutely forbid is stripping out the comments from the source code, or only shipping generated source files (but not the code which generated it). And arguably, git history is much of the same thing as comments. Especially when we have IDEs that can be configured to give us easy access to blame to help us understand the code.

The fact that commit history is not inline with the source code (or even stored as human readable files) makes it a little harder to see/argue that git history could be considered to be part of the source code, and I do wonder where this argument stops? Should the contents of bug trackers and PRs be considered to be part of the source code? What about design documents?