When macOS goes to sleep, it starts a low-power ‘smart sleep’ mode which opens a network connection to see if there’s any updates. It’ll keep this behaviour up every few minutes until you wake the Mac. This is a sleepwatcher script to make it turn off Wi-Fi power (and thus disconnect you from the internet) and tell you exactly what it’s doing (the ‘verbose’ tag), then running it again to turn Wi-Fi back on. When using IRC, this prevents all the timeout/reconnects your Mac fills a channel with when it goes to sleep.

As an alternative, check to see if LaunchAgent has been added to the newest sleepwatcher brew formula. Instead, you could try brew services start sleepwatcher and then create/edit ~/.sleep and put networksetup -setairportpower Wi-Fi off in there (and chmod +x it) then perhaps create a ~/.wake if needed.