A developer voicing publicly being fine with piracy of its own game does not happen to most games. Most devs don't tell anything about it, some get angry at it, and a few make fun of it, like the devs of Game Dev Tycoon did.
It surely helped spreading the word, as it wasn't a "bad" thing to get the game for free. As you didn't feel like a thief or a pirate, it became natural for most people to buy it after a while. The game has many other qualities as well that made it that famous, but the "fine with piracy" aspect is often overlooked.
Gratuitous Space Battles, Hotline Miami, McPixel (even promoted on The Pirate Bay), Amnesia, many Indie games have gone the route where its "not a big deal."
But in general the gaming industry has by and large just not done anything. They are not the MPAA and the whole "kill all pirates" idea is mainly just some executives at the main studios and no one else cares.
And yes, Minecraft at the very very beginning had what is now known as Classic Minecraft and you can still in fact play it for free.
Frankly, I think the best thing to do now is add on more than the 8 or so testers there are, and thus have the game start to gestate in the public. That of course is my shameless attempt at getting to play the game, I'll even do a Let's Play!