LineageOS still use Google services for DNS and connectivity checks. I'd be non surprised if this number will be much more. Also, every third-party app can easily track you and steal data, check the news.
You may be right about connectivity checks although I thought they recently removed Google from those.
Lineage has built on top of Android permission system to prevent most apps from stealing data (Android location permission is probably the most notorious). If you have a rooted device with lineage you can also run XPeivacyLua which fakes out any data that apps "require" to install
