Personally, I am more interested in
Developers: all information (including Personal Information) which is collected through an App as part of the Services is made available to the Developer of that App.
And yes, AFAIK, we are responsible for the 3rd party platforms we integrate into our apps. Just ensure your privacy policy is watertight and you specifically write about the plugins you use and what data they gather. Most are only IP which is fine. GDPR is more about personally identifiable information - name, age, location, email, etc.
I note Corona is totally avoiding my request for app stats (something I remember we used to have) and that we should be good devs and “just be patient”. If I promised something to my players and they didn’t get it I would be lynched in reviews!