Good points, but until Tessa delivers I remain skeptical. Tessa hasn't delivers 20k vehicles to date, bust must do so for 3 quarters to hit 80k in a year. Stating a goal is far different from hitting it; and any hiccup in supply can stall their plans. As for orders, until they are fulfilled they are simply a way to raise funds to stay afloat; and even so customers can cancel preorders if they get tired of waiting or an other option becomes available.
As for GM, if they told their suppliers they want batteries to build more EVs the suppliers would find a way to ramp up production. Absent such a commitment there is no incentive to create the capacity. It's a case of pull demand driving capacity, not the other way around. GM doesn't see the demand, yet, so they are unwilling to produce more vehicles they may not sell.
If you do the math, you can see Tesla has already delivered 53712 through three quarters this year. They plan to deliver 25500 in Q4 which brings it to 79212. I expect them to beat 80K easily. The rumor is that they will announce Autopilot 2.0 this Wednesday (10/19). That will definitely bring in new buyers.
As far as GM goes, they don't seem to believe in their product if they are only limiting it to 50K units. Building battery capacity doesn't happen overnight.
I recall how Apple got a leg up on the competition by locking down all the flash inventory as the smartphone market was about to take off. That's what Tesla is doing with the gigafactory. This is how a company takes market share.