Bug introduced in 10.4 and fixed in 11.0.1
As noticed by Alexei Boulbitch, below one of my answers, there appears to be an unexpected issue with VertexLabels in JournalArticle stylesheet:
SetOptions[EvaluationNotebook[],
StyleDefinitions -> FileName[{"Article"}, "JournalArticle.nb"]]
GridGraph[{10, 10}, VertexLabels -> None]
Vertex labels appear despite the explicit VertexLabels -> None option.
When/where are those labels settings overwritten? Should I expect that?

GridGraph[{10, 10}, VertexLabels -> None, VertexLabelStyle -> Opacity[0]]– Mike Honeychurch Apr 19 '16 at 10:44ClusteringTreewhich is supposed to display only leaf labels. – Szabolcs Apr 19 '16 at 13:24