I would be bad business practice to discount cars without knowing demand.
Sometimes when demand outstrips supply, they mark them up.
Other times, they get a new model and it sits there, unloved, and discount it to move it.
Ordering takes the 'coin toss' factor out of the equation.
I have a hunch that demand in California will outstrip supply until after Dec 31 as people want to claim the tax credit. In 2019Q1, it will be interesting. Tesla will have little to no tax credits left, and create and even bigger gap in pricing.
I could be wrong, but Jaguar has been doing quite a bit of marketing for an EV.
The fact that Tesla Model S/X is selling well, and the i-Pace is cheaper and has more features as well as the Jaguar brand recognition, would lead me to think that some Tesla buyers will cross-shop. This could create a situation where i-Pace demand exceeds supply.