I dunnoh. IPv6 is pretty widely distributed at this point: https://www.google.com/intl/en/ipv6/statistics.html

On the other hand, RISC-V seems to be used so far primarily as a stalking horse to keep ARM in line.

IPv6 is working so well that people often miss the fact it's being used all over the world. Which is probably the greatest endorsement for consumer side IPv6.