Another backer interested in a GOG key.
GOG says they don't have problems sending free keys to developers for backer. I backed a lot of games that provided gog keys. And some didn't. In the other hand, I also heard GOG didn't like giving keys to backers that also get steam keys. They provide gog keys as long as are the only keys you get. This is not confirmed, though. Only rumors.
And there's the fact that the distribution is done through humble. The only other kickstarter that got me keys through humble was Broken Age, and after a while. So I don't know how straight forward it is.
But, yes, drm-free gog versions are a lot better that humble bundle ones. I have several drm-free in humble bundle (classic indies not in gog), and you whatever they put. Sometimes installers. Sometimes zip/rar files directly. Is not always easy to know the release version. They don't keep track of versions or updates. It's kind of a mess.
So, basically, everyone expects a steam key in a kickstarter. And the gog key should be the drm-free standard, whenever a gog release is available.