On the contrary, I don't think we've seen any evidence that this is an adaptive spoiler. We've seen vehicles where the spoiler is up, vehicles where there is a flat piece where the spoiler would be, and vehicles with taped over attachment points. There has not been a single series of photos that shows consecutive shots of the same vehicle with the spoiler in obviously different positions. What we do have is evidence that the spoiler stays up even in stop and go city driving where it serves no aerodynamic benefit.
This leaves the following potential conclusions besides it being an adaptive spoiler:
1. Model X has an optional fixed spoiler. On vehicles with the option, it is fixed in an upright position. On vehicles without it, there is a flat piece of trim over the mounting points.
2. Model X has a standard fixed spoiler, but it was a late addition to the test vehicle fleet. Earlier test vehicles had masking or a flat piece covering it, but what we see now is what the production vehicles will have.
I do think the spoiler greatly enhances the look of the Model X's rear end and would select it even if it provides no aerodynamic benefit, assuming it's not outrageously priced or Performance-only.