When doing an API call using sites & titles, the result doesnt distinguish between

a) titles which do not have a corresponding wikibase_item, and
b) titles which can not have a wikibase item, e.g. the title doesnt exist, or the title are not permitted on Wikibase (talk pages)

i.e., all of the following only say 'missing'

Non existent page:

http://www.wikidata.org/w/api.php?action=wbgetentities&sites=enwiki&titles=Test_page

https://en.wikipedia.org/wiki/Test_page

Redirect page:

http://www.wikidata.org/w/api.php?action=wbgetentities&sites=enwiki&titles=Main_page

https://en.wikipedia.org/wiki/Main_Page

Talk page:

http://www.wikidata.org/w/api.php?action=wbgetentities&sites=enwiki&titles=Talk:Main%20Page

https://en.wikipedia.org/wiki/Talk:Main_Page

Version: unspecified
Severity: minor
Whiteboard: u=dev c=backend p=0
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=45509