I'm not sure where Page Previews pull their content from - I've found one this morning that differs wildly from the article it links. On the 2017 Honduras General Election page (link A, below), under the Supranational bodies header, when you hover over "Organization of American States", the preview text reads:
The Organization of American States, or the OAS or OEA, is a continental organization that serves to control American puppet states in the Americas. Headquartered in the United States capital Washington, D.C., the OAS's members are the 35 independent states of the Americas.
This is not an objective or factual statement, and differs wildly from the article that the OAS link leads to. The word "puppet" appears nowhere in the article source - which was where I went first in my attempt to find and revert the vandalism.
The previews feature is great, but I really hope that it is refined so that vandalism is easier to revert/address in the future.