Maybe a small point, maybe not...
My understanding from other articles is that Guillaume has not filed a suit, but sent what in US law would be a cease and desist letter. Which the publishers can respond to, or not.
Not a small point at all. It costs little to send a cease and desist letter; starting a lawsuit is a much more serious, expensive and laborious process. Also, the claims in a lawsuit are supposed to be verified (signed under penalty of perjury) - at least in the US. There is no verification and no risk of committing perjury involved in simply sending a letter. Many a cease and desist letter has been sent with no follow up. I have no idea what will follow here, but there is a big difference between sending a letter and starting a lawsuit.

