When a document is created new, only a draft variant exists. However, the document variant should already contain the hst:page layout.

Since hst:page child node is by default skipped between unpublished and draft, it means that after the first commit editable instance when an unpublished is created, the hst:page child node should move from the draft to the unpublished

Implementation detail

Most likely it is simplest to fix this in CopyVariantTask where when copying from draft to unpublished is done and there is not yet a unpublished, make sure to move every child node that has the mixin 'hippstd:skipdraft' from the draft to the unpublished. Make sure to add a test for this in DocumentWorkflowSaveUnpublishedTest