How does massdrop work? And what happened with Scythe?
Essentially they make a deal with a distributor or retailer to get something at a better price based on how many people buy it. In a method similar to Kickstarter you commit to buying it and at the end of the time frame you are charged and then you just have to wait for the game to arrive. Shipping usually takes a couple days longer than usual because the games first go to Massdrop, then Massdrop sends it to you.
As for the Scythe bit, the game was up on Massdrop a couple weeks ago and the designer/publisher got up in arms about it because they made the deal without his knowledge. He didn't want such a recently released game on Massdrop because of how it may be perceived and so on. Thus creating the joke of being an "official" drop.