Patterson and Waterman detail exactly what they we’re thinking during the design of RISCV in the RISCV Reader and Cray is mentioned in multiple places.
Cray gets mentioned in the Reader 3 times, the simplicity quote, the pioneer quote and the timeline comparison with the Iliac-4 (p. 80). Waterman's thesis does actually give some credit:
The CDC 6600 [95] and Cray-1 [82] ISAs, in many respects the precursors to RISC, each had two lengths of instruction, albeit without the redundancy property of the Stretch.
https://www.goodreads.com/en/book/show/36604301