Ezautosave tries to update a hidden preview page as edits are made (even before clicking to preview a page). However, if the preview fails for whatever reason (if the template references the location on a first draft), then object data gets corrupted when a draft is published. There were cases where a couple of the fields were empty after publishing the object. A developer issue where you don't handle the location properly should break only the preview; it shouldn't also break data.