IIRC based on the source paper the "verbatim" text is common stuff like legal boilerplate, shared code snippets, book jacket blurbs, alphabetical lists of countries, and other text repeated countless times across the web. It's the text equivalent of DALL-E "memorizing" a meme template or a stock image -- it doesn't mean all or even most of the training data is stored within the model, just that certain pieces of highly duplicated data have ascended to the level of concept and can be reproduced under unusual circumstances.