If it wasnt supply constrained and they sold say 1.5m retail I'd have guessed a natural 20% digital attach ratio for this. That is 300k digital. So i guess all things considered ~2m isn't beyond the realm of possibility it's just mind blowing and hard for me to accept..
From what I've heard the game has small download size so that should help. That's the biggest detriment to digital games, the file sizes. Anyway 33% digital isn't too high with games like Destiny 2 having 50% sales digital on consoles and this an online focused game.