I personally observed 6 third-gym promotions in the past 4 months going as expected, one of which was in the last week. That’s 1/17^6, or 1 in 24 millions if the choice were random.
Not saying you or anyone citing a counterexample is lying, but we humans can make silly mistakes. The system isn’t exactly the simplest. Did we forget to add the likes from the second photo? Misclicking a nearby stop in another L14 cell? Showcase stops? Delayed sync?
Once in a while we even get bizarre misleading cases like this: Photo Appeal: Wrongful deletion of an existing Wayspot photo due to false mass-reporting - #25 by doomzdays
Or an unknown niche factor could be responsible for the rare counterexamples that people are citing. Seems unlikely though.