Assume that anything that you do in an app can (and probably will) be tracked by the app developer. There's no need for third party libraries to track the usage of apps.
For example in a company I worked at, we didn't have tracking/analytics libraries in our apps and webs. But we were still tracking our users, sending all the events to our own servers, which then were transformed into data that could be analysed. We weren't sharing it with any third parties or advertising networks, but we were tracking usage of our apps. Which we were using for user experience improvement and more importantly, for conversion (of users into purchasing customers) rate improvement.
Sure, those events were anonymised and didn't contain what's legally considered PII data. But still, we were tracking our users within our apps so that in the future, we could extract more money out of them.
That's actually when I realised how important privacy is, and how the economic models of current tech businesses incentives this behaviour, so no one doing the tracking thinks they are "the bad guys".