On the point of Idea 1, I missed the point where they try to make sure the text is not in the training set, which is good, but the anonymization it mentions is I think only website anonymization, the anonymization is I think more like stuff like

"President Bush in the state of The Union last month said"

is a statement that should only have been written in a factual document during the Pre-AI era, enough of those and the AI might turn that into math that says Reference to X as being current means NOT AI where X is a range of things that nowadays can only be referred to as the past, except in fiction.