I feel like, if we're going to divide playstyles into ages, I think the Old School/New School divide does really say anything about a singular style. Instead, I think it's more helpful and more realistic to drop the binary (because it's not binary) and adopt something more nuanced. Hell, robbing from comics, you could have Golden Age refer to what's people here call "old school D&D", Silver Age could work for the 80's, with its emphasis on story and characters, Bronze Age for more narrative games like Fate, etc.