I thought someone might make an argument for style vs. time frame and immediately wondered if that would make Byrne's X-Men Hidden Years Bronze Age or Kurt Busiek's Untold Tales of Spider-Man Silver Age even though both are from the late 90s? I think you can define Silver Age, Bronze Age, and so forth as a style that existed at a particular moment in time--the "official" start or ending of said periods are debatable, but I'd argue WCA is well past Marvel's Bronze Age period which many claim ended at the start of Secret Wars with its first of a kind year long event.