shaglio
The Prince of Dorkness
Another possibility is that they release a Scenario Tool Kit along with a couple new scenarios (which the achievements are for).achievements can be anything from making a scenario, to playing someone else's, or they can just be a way to categorize the various achievements with the patch/DLC/XPac they will be added in. Wouldn't be the first game to do it. It is not as far fetched as you make it out to be.(referring to the names) You are already doing it with this season pass thing.
I'm not suggesting that this IS what the STK stands for, but I'm willing to support any reasonable possibilities.