The rule is that titles shouldn't be changed from as authored without reason. In this case, the submitted page used "construction materials" but not "cinder" in

The rule is that titles shouldn't be changed from as authored without reason. In this case, the submitted page used "construction materials" but not "cinder" in its title and subtitle. Maybe the submitter realized that and improved it within the edit window, or a moderator fixed it. I imagine that "cinder" in this context could confuse non-native English speakers.