I believe e the article’s emphasis of this point may be overstating its relevance: the editor’s copyright claim in a derivative work is identical to that of an author. The former’s only distinction is that reproduction requires consent from both the original author and the editor.
I believe the real issue may be more of the delianation between different “works”. I. e. is the Linux kernel a singular work, allowing anyone who contributed significantly to claim copyright protection on the whole, or does the plaintiff in this case only have a claim to the specific module they contributed to.
In any case, this was only about the injunction, and the plaintiff’s case probably suffered most from being overly broad. It appears that the missing distinction between versions the plaintiff may or may not have contributed to was also relevant to making a withdrawal the better option, tactically.
As to that motivation, it may be interesting to note that court fees and costs for lawyers differ significantly if a judge ends the procedure with a written ruling vs voluntary withdrawal. I’ve personally seen judges advising the parties of the likely outcome if they were asked to rule, and strongly encouraging one side to think about withdrawing their motions.