you’re fine using lineageOS with microG and utilising it for cloud messaging, i.e. notifications. the actual content of the notfication doesn’t go through google (or apple), a push message just signals the telegram client there’s activity. then the telegram client wakes up, fetches the message from telegram servers, constructs the notification in-app and then displays it.
google doesn’t have access to the contents of it, but harvests lotsa metadata that microG (as opposed to full-featured play store services) somewhat ameliorates.
having said that, you should make every effort to ditch telegram as well, for a buncha reasons.
you’re fine using lineageOS with microG and utilising it for cloud messaging, i.e. notifications. the actual content of the notfication doesn’t go through google (or apple), a push message just signals the telegram client there’s activity. then the telegram client wakes up, fetches the message from telegram servers, constructs the notification in-app and then displays it.
google doesn’t have access to the contents of it, but harvests lotsa metadata that microG (as opposed to full-featured play store services) somewhat ameliorates.
having said that, you should make every effort to ditch telegram as well, for a buncha reasons.