Well officially they haven't picked a date. I think the April 1 date was listed first so as not to panic the locals and APs into scheduling a last minute trip - 2 weeks is a lot better to take than 2 months. As for the June 1 date for booking, at the time not enough was known but, with a wary eye on the Shanghai changes being looked at, they probably just drew a line in the sand at June 1. Easy to erase a line in the sand. Some folks had bookings being cancelled today that started on May 31 for a week or so into June. I was hoping one of them who called would have asked to just drop the first day and see if that was OK - but so far as I know no one has tried that yet.