Hi!
During the data reload for geospatial service enabling, we have discovered a problem with Wikidata dumps (https://phabricator.wikimedia.org/T133924). The effect of this problem is that some items are missing from the dump. Dumps starting 20160418 are affected, previous ones seem to be fine.
The immediate fix for this would be to reload the data from a correct dump (20160411) and re-sync the data since then. Unfortunately, this may take some time (a day or so for reload, and another day or so for resync), and until then you'll see some missing data on query.wikidata.org. Please be patient until then.
I apologize for the inconvenience caused, and will continue to research the cause of the missing data and then fix it. I'll update the ticket when we have new info.
Thanks,