An interesting detail is that if you look at that Wiki entry, there is an informal study showing that this “rule” is not accurate.

> In 2015, a study of 26,000 articles from 13 news sites on the World Wide Web, conducted by a data scientist and published on his blog, found that the majority (54 percent) were yes/no questions, which divided into 20 percent "yes" answers, 17 percent "no" answers and 16 percent whose answers he could not determine.