THIS!
I think themes and publicity combined probably drove a lot of new interest, and Disney redesigning the page to eliminate link sharing (purposeful or not) impacted the veteran community's ability to virtually guarantee entry.
If it was a design decision, I wonder if they got enough complaints about not being able to move your own queue (due to wifi outage, having to commute to work during the wait, etc) if they'd reconsider adding it back? If it was indeed on purpose and they intended to break up the clique, I think they are going to regret it. The community that's been created around rD is something a lot of companies work really hard for, and to purposefully destroy that is truly shortsighted.