Can any headline that ends in a question mark be answered by the word no? No.
Here’s a quote from that wiki page you linked to:
A 2018 study of 2,585 articles in four academic journals in the field of ecology similarly found that very few titles were posed as questions at all, with 1.82 percent being wh-questions and 2.15 percent being yes/no questions. Of the yes/no questions, 44 percent were answered "yes", 34 percent "maybe", and only 22 percent were answered "no".
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.