quite a good selection of permits were available, even for Thu and Fri dates. Is this typical that so many open up after May 1?
No, I don't think it is typical. But then I haven't paid that much attention to what was available before.
There are still quite a few day hike slots available, but the overnights are down to a sprinkling of singles. In a week or two, there won't be anything left. Only a few odd slots may show up after that -- slots released by people who have paid for permits and someone in their group cancels. These usually show up just a few days before the hike date.
