These are my questions when reading the Nature news article although it has a quite different title “Think preprints are unreliable? Analysis of 70,000 studies might change your mind”.

The central conclusions of biomedical preprints rarely change following peer review in a journal, according to a study posted on the preprint server bioRxiv this month. The research also found that studies that appeared first as preprints are retracted at roughly half the rate of papers that did not appear online before being in a peer-reviewed journal. The authors say the findings suggests that preprints are a reliable source of information, although some scientists say the finding should be interpreted more cautiously.

It is all about this preprint

The primary claim was unchanged in 39.9% of abstracts, minorly revised in 50.0%, and substantially revised in only 10.2%.

Fits my experience, 90% more or less unchanged.