For the people having issues with coordinated cancellations showing up - I have twice now coordinated cancellations with other DISers where the ADRs they canceled did not show up for me when I searched for them. We were coordinating through e-mail, so it's not like a "lurker" could have been waiting to pounce as soon as it was announced.
Both times, I then searched the same time/restaurant but for a smaller party, and then it showed up.
I hypothesize that when the restaurant is particularly crowded (as in at or very close to capacity) the restaurant "reclaims" a couple of the seats and instead makes available a smaller number. Both times the DISers I was coordinating with canceled ADRs for 10 people, and what became available instead was (in one case) an availability for a party of 8, and (in the other case) an availability for a party of 6.
If you're coordinating with someone and the exact reservation being released does not turn up, try searching for a smaller party. It might work!