That's not really comparable. Raspberry Pi added entirely separate RISC-V cores to the chip, they didn't convert an ARM core design to run RISC-V instructions.
What is being discussed is taking an ARM design and modifying it to run RISC-V, which is not the same thing as what Raspberry Pi has done and is not as simple as people are implying here.
What is being discussed is taking an ARM design and modifying it to run RISC-V, which is not the same thing as what Raspberry Pi has done and is not as simple as people are implying here.