I found that there is an object PodTemplate registered in apiserver which we can use as other kube objects.
From the struct definition, PodTemplate contains PodTemplateSpec just as other workload objects, such as rc. But I do not find any usage of PodTemplate object from either doc or code. And rc/ps/ss does not have any reference to PodTemplate actually.
So I want to understand:
The official statement:
The objects exist and can be used. We don't really have a position on it today.
It is hoped that eventually StatefulSets and DaemonSets will have history, like Deployments, and that will make use of this object.