I am sure you can still get some reservations, but you will have to be flexible with your times. We are a party of 6 and I just made reservations for the second week of June, and the times I got were late lunch or early dinner. Also, I had no problem making a reservation for 8:30pm at Kona Cafe, so I'm assuming late dinner times work as well.
The only one that I had trouble getting was Ohana for around 5pm. The first time I called, there was nothing except for at like 8pm. The next day I called again and got lucky and got a reservation for 5:30pm, but our party will be split up.