I have sinned, so don't believe that I'm not guilty of this transgression ;^)))). One of the most dangerous items on a boat is a calendar. Leaving too late (by staying too long) or leaving too early is an issue even on short passages (including a daysail, for that matter).
I was speaking with the captain of PlayStation (a multihull that set a bunch of open ocean records accross the Atlantic and around the world). He said that in the case of a large multi-hull like that, your speed is faster than the storms, so you can avoid them. In the case of a conventional boat, you just have to be prepared for what's out there. (He did not that the scariest time was a crossing to England from the U.S. They ran out of searoom and got "pinned" in square waves of about 50'. That multihull didn't like that a bit. The crew and captain liked it less. He said it was one of the few times he wasn't sure what would happen. Anyway, I digress...)
In the case of bunch of different boats with different speeds, crew abilities, and sea kindliness, as well as ability to take serious abuse -- you just are taking your really trying to thread a neadle that time of year.
Getting through the Gulf Stream (about 250 or more miles from Norfolk) is a two or three day event for most of those boats. After that, assuming nothing horrible is faced (like a late year extra-tropical hurricane, or the like, I believe the race should be more ocean passagelike. However, that period through the Gulf Stream is critical. The "normal" two- or four-day window for fronts coming through with a northerly component to strong winds isn't much of window. Going to Bermuda isn't necessarily a break because I believe it would extend the exposure to Gulf Stream effects instead of simply going across and then down ASAP.
If you go from southern New England, your potential exposure becomes a bit longer. The flaw is all of the boats even TRYING to leave at the same time.
The racing "diasters" of the Fasnet and Sydney-Hobart, etc. where faster boats have a tough, but tolerable time -- and a whole bunch of others have survial experience (sometimes not sucessfully) are evidence enough of this.
Those races are with generally more experienced crews, the availablity and attention of support and rescue operations monitoring, etc. In this case is a bunch of USCG crews out of North Carolina, Virginia, etc., or Bermuda rescue personell who have to jump into to help.
My take-aways: i) A three-day window IS NOT enough, ii) Organizers should consider a "leave now" approach that the 1500 took this year (after the prior problems), and iii) leaving a week or more later than planned is something that boats and crews should be prepared for.
The other course, which a number of people have spoken of is to really leave for St. Marten or the Virgin Islands from father south.