They indicate it comes with their “Loyalist Edition” (sold on their website). There, it states that the Loyalist edition includes “First expansion when released.” That suggests to me that this is the first expansion, which means it should also be available to those that are supposed to get the “free expansion” as part of their backer pledge. I could be wrong, as I don’t actually know, but that’s my interpretation, and I was waiting for an expansion to continue playing. I didn’t think the Crucible DLC was the expansion, as it wasn’t called that.
[Edit] Also this from their Crucible DLC announcement: As a special thank you to those who have been with us at the beginning of Grim Dawn’s journey, everyone who purchased the game through our website prior to/during the Kickstarter (the Kickstarter Campaign ended on May 19, 2012), or through the Kickstarter campaign itself, will receive the DLC for FREE.
So that wasn’t the backer expansion for sure.