There are some obvious words that Google does not like to see appearing in products within Google Shopping, for example swear words and drugs. However sometimes legitimate products can contain key words that get flagged up simply because they may have a double meaning or other, less savoury connotation. Either way they will get highlighted as “Automatic item disapprovals due to policy violation” and dropped from your feed.
When this happens and your products have been incorrectly dropped you can contact Google to get it resolved. Currently though, there is a problem with this and Google are unable to reinstate incorrectly disapproved products that fall into this category. There is no fix date as of yet but hopefully it will be resolved soon.
If you are experiencing this problem you can send your feedback to Google within your AdWords or Merchant Centre account > Settings gear > Send Feedback.