We want this. Immediate concave. Maybe that isn't technically feasible?
It's not so much a question of being technically feasible, it's rather the fact is that it wouldn't really make much sense to add concave for this specific wheel. I agree that concave wheels do look cool, and the example in the poster shown is a very good looking wheel (For that specific wheels, it is 10.5" or 11" wide with an RR face, having the most concave). This wheel has a bit of a backstory to it:
The TC (Technical Circuit) line of wheels began in 1993 with the TC-05 and was designed as a lightweight solution for Honda cars, then the TC-005N was released in 2000. The TC-105N followed in 2006, which featured a 10-spoke design and a spoke reinforcement called the N-Frame which was designed to help impact dispersion. I've attached a photo of the wheel below:
The 10-spoke design was used as it allowed the usage of thin spokes than designs that used less but thicker spokes, while reducing the cavitation area (Side note, if you're comparing wheel weights, do it between wheels that have similar spoke designs). This wheel offered weights almost identical to and in some cases lighter than the 105X. Take note of the PCD (bolt hole) area, where there is a drop center, as seen below:
Some wheels have this feature, some do not, but one other notable wheel that also uses this is the Enkei RPF1. This allows for control of the offset by making this PCD area shallower or deeper between face types without having to extend the spoke to that part of the rim (adding concave). Adding concave makes the spoke of the wheel much longer which does add weight.
When the TC-105N was replaced after a decade of service with the current TC-105X, it had to work not only with the cars of today, but with the cars of tomorrow. Cars that are getting heavier and heavier and gaining more power as standard, all while keeping weight similar to the 105N. The TC-105N has already been used in a wide range of conditions - Team Tilton's time attack racecar, where the TC-105N was used to take the World Time attack record, to SCCA champion's Michele Abbate's FR-S racecar. Even though putting the 105N in stresses such as high downforce with slicks wasn't enough to deter it, WedsSport engineers sought to make the wheel even stronger than before.
As noted in the brochure, material was added in places where it was necessary for structural reinforcement, and removed in areas where it wasn't. Weight was removed in areas where it wouldn't compromise the structure, including on the side of the PCD area. Even a new painting process was used which is estimated to have shed around 1lb. Reducing spoke length and using a drop center is a very easy way to reduce weight, it would be crazy for them not to do it especially when they're going to lengths such as using vapor deposition to apply paint.
tl;dr: adding concave looks cool but in the case of this wheel it wouldn't make sense as it would increase weight, going against the wheel's design concept.
