Even when data are publicly available their use can breach what we call textual integrity. This is a fundamental principle in legal discussions of privacy. It requires that individuals’ information is not revealed outside of the context in which it was originally produced.
First, if you click the associated link link there isn't any indication this is a widely accepted view ('fundamental principle'). I'd never call myself an expert but I've never heard of this.Second, the way I read this is that they are trying to analogize scarping the web to feed it into ChatGPT to someone following you movements in public recording it all.
Even if you believe in their legal theory of privacy is right, wouldn't Google would be far larger offender than ChatGPT?