I have been planning on htis trip for a long time, I would suggest with those who are plan to dry camp not totaly write off not coming down. If the camp grounds do not open there will be MANY people, (even those with reservations) dry camping in any available areas( I plan on sleeping in my truck). I am hopeful the area will support the overflow and from the instagram and weather forecast it looks like it should be good.
https://www.instagram.com/p/BFfYB4mAuEG/?taken-by=overlandexpo
Possibly a bit muddy but still good
https://weather.com/weather/tenday/l/USAZ0068:1:US