But NuttX has more features than traditional RTOS(e.g. FreeRTOS). Actually, Xiaomi uses it in the IoT space which has less real time requirements. Other similar OS(e.g. Zephyr) doesn't append rtos suffix. So, I prefer keep nuttx and nuttx-apps.
I just endorsed nuttx_rtos and nuttx_apps, but Xiao is correct. nuttx_rtos is redundant since nuttx is the name of the RTOS. nuttx_apps are miscellaneous applications tailored for the NuttX RTOS. It really is semantically cleaner.