I'm not sure that camping out will be necessary. Disneyland seems to think there will be a lot of people doing it, but with all of the preview spots available on the 9th and 10th, probable soft openings after that and then extra passholder hours in the mornings, I'm not sure how many people are actually going to want to camp out. Might still be fun for some folks to do. But what are they waiting for? A chance to say that they were there days after tens of thousands of other people had already seen the new land?
By the evening of the 9th, there will be thousands of photos and videos already online. That should help lessen the desire to camp out.
It's one thing to camp out for a new ride that no one has seen or for a special anniversary (like the 50th) and a completely different thing to camp out for something which has already launched.