Yes it does. Think of typical notions of statistical significance when testing one new idea prospectively, say the concept of a p-value, or the AUC used in the paper. Now think instead of a rich dataset and you are free to fish for any of the possibly tens of thousands of signals for one signal or a combination of signals that match your result. Loosely speaking you are overfitting and the threshold for being surprised or having statistical significance is now much more strict.
https://en.wikipedia.org/wiki/Bonferroni_correction
