I'm unsure where you are getting this from. If you watch their presentation for their test tunnel unveiling (https://www.youtube.com/watch?v=nSIzsMlwMUY), it is fairly explicitly communicated that what they are attempting to do is increase the speed at which you can bore a tunnel, thereby decreasing tunneling costs. The rapid production of the tunnel is the product here.
The video linked has Elon saying specifically that they have an industry-standard TBM that they used for the Hawthorne test tunnel. There is no improvement there. They have 2 more machines they are building that are expected to be large improvements over the tunnel status quo for that given size of tunnel they are constructing.
Again, the improvement is not in the tunnel size... they are building their own TBMs, trying to get them to be faster at tunneling than the existing machine that they have.
The video linked has Elon saying specifically that they have an industry-standard TBM that they used for the Hawthorne test tunnel. There is no improvement there. They have 2 more machines they are building that are expected to be large improvements over the tunnel status quo for that given size of tunnel they are constructing.
Again, the improvement is not in the tunnel size... they are building their own TBMs, trying to get them to be faster at tunneling than the existing machine that they have.