I have to agree, we know they are building alpha units since they stated that publicly. I doubt the parts viewed were stamped out, but were more likely one-offs, made specifically for the alpha build. That kind of stuff will come later, when production is actually going to begin. This sounds more like just using the factory space to prepare the alphas.
And yes, it's exciting.

But it's in line with the timeline stated less than two weeks ago, so not a huge surprise. But exciting just the same. (Though it's hearing little things about X technology that makes my head swivel.)