Per the compatibility version KEP, alphas are outside the scope of compatibility version.

https://github.com/kubernetes/enhancements/blob/master/keps/sig-architecture/4330-compatibility-versions/README.md#non-goals

Support --emulation-version for Alpha features. Alpha feature are not designed to be upgradable, so we will not allow alpha features to be enabled when --emulation-version is set.

We current don't have proper safeguards for this.

• Alpha features should not be permitted to be enabled with emulated version
• Alpha APIs should not be permitted to be enabled with emulated version

/cc @aaron-prindle @jpbetz

/triage accepted
/sig architecture
/sig api-machinery