They could, but then when everyone crashes the game, they'll bitch how they couldn't play and fill their vaults, and how its not fair and they are going to go get a refund and how bungie sucks and XB1 for life, and PS4 sucks.... etc
Honestly thought I've only experienced one crash when we were both on that one night. I still expect a few hiccups on launch day.... but nothing too bad. Activision tends to be better than EA on opening day.