Depending on how it is implemented. If it's coded into Android OS that's a bigger problem, if it's included in Gapps, you can just remove them of block their connections on firewall.
If I correctly understand `Last modified: June 28, 2016, they are writing`, this feature should not be available before that date, so either it comes as an update to a gapps or to Android.
Well when you first boot a custom rom like cyanogenmod or replicant or self-compile android, there is no such terms that you have to agree to. So this privacy issue is not with Android Open Source Project, but rather with the proprietary google apps.
If I correctly understand `Last modified: June 28, 2016, they are writing`, this feature should not be available before that date, so either it comes as an update to a gapps or to Android.