Are you sure it works the same way for documents that Google indexed at the time of publication? (Because obviously for things that existed before Google, they had to accept the publication date at face value).
https://www.google.com/search?q=site%3Achatgpt.com&tbs=cdr%3...
So it looks like Google uses inferred dates over its own indexing timestamps, even for recently crawled pages from domains that didn't exist during the claimed date range.
I wonder why they do that when they could use time of first indexing instead.