The CT tires have "about half" the tread depth of the regular Goodyear AT tires - Out of Spec Reviews in his 70mph higways test video.
I suspect this is the reason why videos of the CT struggling in snow/slopes keep popping up.
I have a feeling a lot of R&D was focused on keeping the aesthetic and construction of the Cybertruck. Along with using the cheaper, newer batteries. With things like tires, towing, offroading, snow, etc. being assumptions that would come along with a working truck.
Then, when they looked up after three years and the range numbers started coming back in the 200s; they probably panicked and called Goodyear to see what could be done.