I also wouldn't say 'unknowingly trained', it's pretty obvious what it does, and I think the game even tells you that they want to understands how the POI looks like in 3D.
The other point from article. I took this as experimental, so maybe we'll find out later that they really couldn't get much usable data.
We joke that maybe PoGo didn't get any benefit from his data, but someone did.
Do we have to think? Apparently they amassed 30B images. :)
This was GP's original point - it doesn't take the majority of people playing Pokemon Go to do it in order for them to get 30B images, especially since each scan was like multiple images - you look like a dork doing the scan
But most people probably assumed the purpose was to improve the game, not to train delivery robots.
Or whatever else they end up doing with the data. If, as the article suggests, this ends up adding to the surveillance state by making geolocation of photos more accurate, then I really don't think that's what the players had in mind.