I was on the receiving end of a leak once that basically ruined the entire start of the planned
PR campaign for a release. All the cool stuff that me and others had planned had to go out of the window and be hurriedly replaced.
So any plans Arrow had to slowly leak the news or to have any fun with such a hotly anticipated title are now effectively ruined. It's not just about fans' fun being spoiled, its about all of the people who are working hard on the title now having to change their plans for how it gets revealed.
It's basically just not fair or professional.