Sadly, WSL does not export the same device interface consumed by libusb, so openocd can’t be used without modification. That being said, I was able to load the linux version of both FREEDOM-E-SDK and FreedomStudio (after installing the Xming X Server.) I was able to compile, but not run GDB in the RISCV specific binutils, and the compiler seemed to work.
But ultimately, I couldn’t connect openocd to the HiFive1 board or get gdb to run reliably.