648
FBI Extracts Suspect’s Deleted Signal Messages Saved in iPhone Notification Database
(www.404media.co)
This is a most excellent place for technology news and articles.
To send you a push notification, an app requires a special token specific to that app and your device, kinda like an API key, which can only be generated for a device using Google Play Services. Without that token, a push notification cannot be sent. These tokens expire, so if you used Google Play Services and just turned it off, push notifications will still get sent into the ether - but never delivered - until the token expires, at which point notifications can't be sent anymore. Badly developed apps might still try to send push notifications with expired tokens, I have no idea what Google servers would do with that, but I'd guess they would just discard it immediately.