[csnover]

GPT-4 readily hallucinates data[0], so that seems unlikely, though it also appears unlikely that it would make it any worse!

[0] https://news.ycombinator.com/item?id=34775853

[chatmasta]

GPT-4 can write queries if you give it a schema, but I definitely wouldn't rely on it to generate any actual data.

[nradov]

The government has a databases of synthetic medical insurance claims that developers can use for testing.

https://www.ahrq.gov/data/innovations/syh-dr.html