K8s can schedule pod with different priorities.

I'm not sure I agree here, could you refer me to the docs on this ability in k8s ?

So maybe no real scheduling means there is no ClearML scheduling after applying pod to k8s.

That is correct 🙂

Does it will implement in the future?

Yes, this is enterprise feature, in the community you can specify --max-pods limit (which will cause it never to pull a job if it hits the max-pod limit)