Do the authors ever reveal if they detected any would-be hackers?

No.

This is an adorable project that assumes people who are familiar with nmap regularly scan whatever they can.

It’s cute, but I’d expect it to be pretty dull to watch.

https://zmap.io/ https://github.com/robertdavidgraham/masscan

it will be attacked within minutes, you should start a honeypot and see for yourselves