kubectl caches API discovery results without being aware of its changes. Registering/Removing a new API service with api aggregator results in a change in API discovery but kubectl has no way to know the result is changed.

Possible solutions:

short term - implement e-tag for API discovery
long term - move to OpenAPI for api discovery

This is possibly a release blocker.

cc @lavalamp @pwittrock @dchen1107

@kubernetes/sig-cli-misc @kubernetes/sig-api-machinery-misc