Are you going by Thrill Data information? I can't speak to the details of how they collect data, but I think they keep pinging constantly, so they are posting ideal results.
Just yesterday, Tiana's was out of G+ at 8am, but later in the day there was spotty availability. Thrill data shows those additional drops, and in that specific case- maybe many park goers did get lucky.
But I could also see how someone who searched at all the wrong times might not see any availability after 8am, if they looked and refreshed during all the wrong time intervals. And well, there's good reason for the average parkgoer to think Tiana passes were all gone by 8am for a new ride experience. I'm not in WDW right now, I'm just trying to explain how there could be a difference.
At least that has been my experience.
Mind, I've personally always been able to get more G+. Though I did have one bad day once at HS during a holiday week back when passes could not be modified. The modify feature is key to making any of these workable, IMO.