2K's site has the list, but I prefer
http://www.thesmackdownhotel.com/wwe2k17/roster/ because it's in alphabetical order.
I remember a lot of the first 2K15 hype articles saying that 2K was able to have a somewhat later cutoff on getting people in due to their scanning tech. I don't think that's been proven true though. Cutoff does seem to still be around Mania.