I don't think making mass market products or having a long supply chain necessarily means you can't keep secrets. I mean, Nintendo seems pretty damn good at keeping their cards close to their chest, arguably even better than Apple in that sense, and they've got a decent supply chain and mass market products. Same goes with Valve.

Quite a few smaller companies there are the same way too. You very rarely hear about leaks coming from Retro Studios or Rare for example. Companies have definitely have a more secretive culture, and while it won't 100% stop leaks, it'll definitely keep them to the bare minimum.