My argument is that the LLM is just a tool. It's up to the person that used that tool to check for copyright infringement. Not the maker of the tool.

Build an inkjet printer exclusively out of stolen parts from HP, Brother, and Epson and marketed as being so good that experts can't differentiate what they print from legal currency (except sometimes it adds cartoonish moustaches). Start selling it in retail stores alongside them. They would battery be announced, much less stocked on the shelves before C&D letters and/or arrest warrants arrived.