Neither will an ESP32 that needs permanent internet acccess and relies on a publicly available API usually running on Linux servers. Running on a realtime OS is not relevant for zclaw.

It has nothing to do with being realtime. Most mcus are also not running any realtime OS.

What matters here is how dynamic and tightly coupled are the os components. On an embedded system, most of the system and their dependencies are monolithic, without any live updates. The system tends to behave almost deterministically after every reboot.