For better or worse the use of GPL is going away, even the future of Linux kernel is not guaranteed.

In the realm of IoT FOSS UNIX like operating systems, all the contendants are using a mix of Apache, MIT and BSD licenses, including the ZephyrOS sponsored by the Linux Foundation.

When the GPL generation is gone from the face of the Earth, it won't last long that UNIX-like OSes get another steward alternative to the Linux kernel, with a more appealing license to big corps.