People "realized" this when Apple began doing it and honestly told people about it. It is trivially easy for you to turn off location sharing permissions for iPhone Analytics if you so desire. It's right there in Settings.
Are you maybe talking about the location cache?[0]
That wasn't to any Apple server, it was a local cache that apps couldn't get unless they used a root exploit; was safe on your backups if they were encrypted; and was discussed in the TOS (Ars's sensationalism about "without your consent" notwithstanding).
https://m.imgur.com/kldOZ54