These RISC-V cores are an internal implementation detail of their GPUs, so although the architecture is open they aren't really open in the sense that you can a

These RISC-V cores are an internal implementation detail of their GPUs, so although the architecture is open they aren't really open in the sense that you can actually program them. Nvidia is doing it to save a buck because they no longer have to roll their own architecture (as they did previously) or pay for ARM licenses.