Watching the reservation availability the last few days, I've come to a primary conclusion.
Starting Tuesday June 15, they are increasing capacity by a substantial amount at both parks.
I check constantly, and literally Nothing has been available at either park between now and Monday June 14. It has been that way since last weekend. Usually see dates pop up here and there, but this time, Nada. The only date after 6/15 that has remained unavailable is Saturday 6/19. A few days ago, it was opening up occasionally, but now it's remaining sold out. So even with larger capacity, Saturday is obviously still the most popular day.
If other days start selling out, expect them to keep the Reservation system in place for awhile longer. I imagine Friday 6/18 will be the next to go, but if only Saturdays are selling out, it bodes well that they might get rid of the Reservations. Or perhaps make non-weekend days "Good To Go."
The increased capacity is also apparent with Soak City reservations. Post 6/15, it's completely open. Some days are showing 10:30 or 11:00 arrival times, but while weekends have booked up in the past, they appear to be quite available. So they're still staggering the arrival times, but have added so much capacity, that the earlier times are staying available rather than filling up. I can see them dumping the timed reservations, or perhaps the whole thing if even weekend dates aren't filling up. Right now you can still get in at 11:00 next Saturday, so even that most popular day appears to be a long way from selling out.
I view all of this as Good News & Bad News. Good that reservations may be on the way out. Bad that capacity increases will make the parks more crowded. That won't necessarily result in longer waits for rides, because capacity will increase there. It will mean more people in the park in general. Longer food lines and much harder probably finding a place to sit or eat.