Reading the source code, I find this:

function recordInstall() { if (utils.prefs('install_recorded')) { return; }

sendReq('install'); }

So the if statement that the OP highlights does not actually phone every time it is called like the OP claims, but only on the first install. The message that the add-on sends to ghostery.com includes the Ghostrank preference, the version of Ghostery, the OS, and the Firefox version (Android or desktop). That said, it does appear that the add-on phones home on each upgrade, and I don't see anything in the Ghostery Privacy Policy about this (it only discusses GhostRank).