The deposit server emits <entry> elements in a few places (off the top of my head, GET Col-IRI and the deposit receipt), but it does not follow the RFC 4287 definition:
o atom:entry elements MUST contain one or more atom:author elements,
unless the atom:entry contains an atom:source element that
contains an atom:author element or, in an Atom Feed Document, the
atom:feed element contains an atom:author element itself.
[...]
o atom:entry elements MUST contain exactly one atom:id element.
o atom:entry elements that contain no child atom:content element
MUST contain at least one atom:link element with a rel attribute
value of "alternate".
[...]
o atom:entry elements MUST contain an atom:summary element in either
of the following cases:
* the atom:entry contains an atom:content that has a "src"
attribute (and is thus empty).
* the atom:entry contains content that is encoded in Base64;
i.e., the "type" attribute of atom:content is a MIME media type
[MIMEREG], but is not an XML media type [RFC3023], does not
begin with "text/", and does not end with "/xml" or "+xml".
[...]
o atom:entry elements MUST contain exactly one atom:title element.
o atom:entry elements MUST contain exactly one atom:updated element.This is not very high priority, I don't see a reason for clients to need most of them.
Preserving atom:title and atom:id from the deposited metadata could be useful though, to allow clients to keep track of their deposits.