I honestly think capacity will be increased again by June.
The AP is wide open in June because those of us who visit often don't want to tie up their 3 visits now for days a few months away. You'll notice that the AP bucket fills almost a month at a time. Because of the reservation system, I booked 3 visits in April as soon as my March visits were done (well, when my blackouts started). Once I finish an April visit, I book a May day. And so on. So I won't book June until May, and my guess is most AP's are like that too, so it gives a false picture of the June AP being "empty" (though June does begin blockout for Silver and weekday, which will help!)