I could be wrong, but isn't Intel's management engine running Minix?
Intel is not required to share the source code (and they don't).
If MINIX as a publicly developed project does die then it's a data point for copyleft licensing being more robust.
And it's exposed on the network because its used in Intel Management Engine.
Meanwhile the Linux kernel is going strong with many companies helping maintain it.
Seems like a shortsighted decision on Intel's part.
Linux only drops support when nobody uses the architecture anymore. And if Intel is using it for ME then there's a big case to be made for keeping it.