The specification doesn't say the state should be cloned:
https://dom.spec.whatwg.org/#concept-node-clone

The standard in this place is vague. But now browsers (really all) is copying the state of radio buttons and checkboxes. It is logical to bring everything to a consistent form.

Spec discussion https://stackoverflow.com/questions/27193301/node-clonenode-inconsistent-with-dom-spec

Refer to spec in step 3 you must copy Attr. But actual you copy properties (opposed to attributes) of input type=text, checked of radio. Copy "selected" properties of select's option.

Step 3 is for the case when the processed node is not an element, but since the internal state is never exposed as an attribute (it's a technical term defined in the same spec and in your case only 'name' and 'onchange' are attributes) as per DOM spec, that step is not applicable here and Chrome matches the current spec. You, or someone else, can/should open an issue in the spec's repo to clarify cloning of the internal state - https://github.com/whatwg/dom

Yes you are right. Spec defines cloning steps only for script and input elements.
I was told there https://github.com/whatwg/dom/issues/644 that the spec is a conservative thing to correct mistakes in it.
Maybe this can be done through implementation? 

Closing according to the conclusion of https://github.com/whatwg/dom/issues/644