Espressif, who produces the extremely popular EPS8266 and ESP32 products has in the past used a Xtensa CPU core. Their latest parts use a RISCV core. This should eventually give us more software options on these devices.
Nice main CPU is RV32. I can see it use RISCV32 ISA based MCUs in multiple places there, H/W Crypto, RF, baseband …
so apple seems to be interested in RISCV for MCUs in future M1 cores