I just got a notice from TMG to Kickstarter backers announcing a free joint stretch goal to obtain a Samurai dragon meeple. However, I couldn't make head nor tail of the page they directed me to. If someone would explain it to me, I'd appreciate it!
Eric - if you scroll down far enough under stretch goals, you'll see what is being referenced here - essentially if Meeplesource gets a total of 1000 backers this meeple will be thrown in for free with any pledge level that buys meeples.
In short, you still have to buy something to get it...and it looks like you have to pay at least $8 for the cheapest set of meeples (for Scythe) or else at least $10 for a set of 8 of 1 type of meeple.
I don't think he is intended to be added directly to the game in any specific way.
The kickstarter is just to sell custom meeples. There are some for specific games but most are just to give your meeples some personality. I think they're just trying to cross promote between the two companies and using the kickstarter update as targeted marketing.