I don't hate the CT, it's just that the design is not for me. Let's face it - Tesla & Elon set themselves up for criticism from the get go. "Bulletproof glass", "Tows almost infA lot of hate towards the Cybertruck as expected on a Rivian forum.
Your guess may be very close. A recent patent application for the 30x grade listed 1.8mm as a thickness. Thickness is $$$ when it comes to stainless.My guess is the main exoskeleton will be reduced to 2mm thickness. The front fenders and hood will be even thinner.
Why? Affordability, vehicle weight and crash worthiness.
It's cool that Tesla is optimizing the stainless, but I have to chuckle a bit at the press this is getting and the hype that Tesla is spinning on this. I have some experience with this - our engineering company has done process control work for 30 years for a high performance stainless mill. There's really no earth-shattering discovery going on here. It's every day metallurgy. It's well know by metallurgists that changing % composition, temperatures, annealing processes and rolling techniques has different effects on the crystaline structure and therefore performance characteristics of an SS alloy. Tweak the amount of chromium, nickel, manganese, etc, electroslag and vacuum arc remelt to eliminate impurities, (Google those terms if you are curious about it) control the furnace atmosphere, etc. It's similar to tweaking a cake baking recipe. In the graphic, you can see that the new alloy is a variation of well known alloys - 301, 304L and 316L. That's why it's currently known as 30x. If it becomes a true industry standard, that designation would change. The additional elements, extensive processing and energy input is what makes stainless so much more expensive.