Flask’s page doesn’t mention django, an avr microcontroller’s page doesn’t mention x86, my bash static site generator readme doesn’t mention wordpress...
None of this is strange.
Why are you being obtuse, rather than trying to be clear?
RISC-V is the major Free and Open CPU. RISC-V can run on FPGA. It's natural to want a comparison of this project against RISC-V, especially considering the write-up mentions the less successful OpenRISC project.
This page appears to have been written in summer of 2016. Back then RISC-V didn't even have a stable privileged instruction set yet, so there wasn't really a RISC-V to compare it to in a meaningful sense.