This is not "hacking". This is information derived from publicly available information, presumably a quite trivial inference. If it is public information that x=2 and y=3, then x+y=5 isn't suddenly private information, just because it requires a trivial inference.
Photos taken on phones often contain GPS data. If someone publicly shares a photo they’ve taken and the data isn’t scrubbed, it’s trivial to find out where the photo was taken.
Just because it’s easy to uncover doesn’t mean it’s fine to go off and broadcast it. That’s doxxing.