Comes out Thursday on Steam. If your exclusivity period is only 3 months then why bother having one at all?
I think they realize the die hard fans and must have day 1 people will buy it anywhere. 12% vs 34% is a big difference for those people. Once that period is over it makes a whole lot of sense to put it on the more popular client. Player base = sales for multiplayer games, although this can likely be played just fine offline like the others.
Also new DLC is coming out same day apparently. Steam page has no mention of Denuvo, which is interesting. I assume it will be updated before the game goes live.