Not really shocking. This October was way more packed than usual. Of course Red Dead Redemption was a big hit, but having Call of Duty release in October instead of the usual November sealed the deal. Just look at the big games released last October vs this October. Some good stuff last year, but of course this year was bigger. There's more variety in 2017, but it's easy to see why 2018 was bigger.

October 2017
Mario Odyssey
Assassin's Creed Origins
Forza 7
Middle Earth: Shadow of War Wolfenstein II
Evil Within 2 Gran Turismo Sport South Park Fractured But Whole

October 2018
Assassin's Creed Odyssey (much earlier in the month too)
Red Dead Redemption
Call of Duty: Black Ops 4
Forza Horizon 4
Soul Calibur VI Super Mario Party