That's Not How We Explain Things.
Much as I love New York, it seems to me that the signage has deteriorated greatly - nowhere more so than on the subway. The most prominent part of this poster delivers a message that is incorrect for the majority of the day on which it appeared.
It would have been much clearer to announce that there were "No late-night Brooklyn bound trains" at this station, but that didn't happen because someone has decided that the conformity of communications format is sacrosanct. Consequently, timings appear in a small, unobtrusive header because the internal communication rules dictate that, even if doing so renders the message opaque.
Something to think about when you next hear the argument that you can't do that because "it's not on brand".