I don't think anyone expected it to be soon. Steam will start caring when the AAA companies that have already fled to EGS (Ubisoft, Take-Two) CONTINUE to release games early on EGS, like Assassin's Creed, 2K, etc. Division 2 and BL3, as well as all the indies and other AAA games like Metro, were baby steps. WB has shown it's still "loyal" to Steam.
The real problem is that 90% of them are only timed exclusives, not full exclusives, so Steam knows it'll see that dollah sooner or later. But, this digresses from the thread. Kinda.
we don't know for sure. I'm sure it's case by case. But WB has no reason to want it to unlock so late on PC. Steam just F'ing up the release time makes more sense than WB saying "you know, let's not do a midnight release on PC." I can't remember MKX's release time and I didn't pay attention to Shadows of War. Does WB have a history of this on Steam?
Steam isn't always accurate about release times, tho. Sometimes even for the better (games playable before the "game will be unlocked at ____" time).
I mean, I've seen some release times be at 10am, some at 2pm... Why would those games be so negligibly different?