That would be a terrible tradeoff. The ship has already sailed and a lot of public AI content will not be their own. Deliberately making their product worse to reduce identifiability of AI inputs by 25% just doesn't sound worth it to me. Is that what you would pick if you were in charge of anthropic and wanted to maximise the company's product?

And what wisdom do you think they would be missing if unable to distinguish three word written pieces? Keep in mind that most sources are not inherently trustworthy just because they rate as human written, too. You need some other way to rate text in all cases.