Thanks billycar11!
From the description I see that the script will flash a 760MB file, the KK 4.4.2 (KDA20.62-10.1). So I won't be afaid that when I wait for some months even if Moto patched their OTA for this bootloader exploit, the unpatched bootloader is still in (KDA20.62-10.1), which I assume is build 183, so I will still be able to use this exploit, as long as my phone is in JB (4.2) state?
There's two things to be aware of. First, it's not the bootloader you should be concerned with. It's the TZ (trusted zone) partition. That's where the unlock exploit lives. Second, however, is that the phone must be rooted to unlock. So let's say the next OTA by some miracle doesn't patch the TZ but does patch root. You'd be unable to unlock as a result of no root. So, you want to stay on KDA20.62-10.1 build 183 until you unlock. That is the version that can be rooted and will allow the unlock. Any OTA update will update the TZ partition, after which, it's likely game over again.