You probably only have disabled the reception/display of push notifications. They are still being sent (given that it’s not your iPhone that sends them, but cloud services).
If it helps - but does not completely answer:
Q: If an app attempts to send a notification to an iOS device that is either powered off or has no network connectivity push notifications need to be kept in queue.
For how long does Apple retain notifications to allow the device time to contact the APNS servers?
A: “It depends on the service that sent the
notification in the first place. The service (i.e. the backend system that supports an app such as Facebook or any other app) sends their
notifications to Apple's push
notificationservice over a HTTP/2-based API. In that API it sets a parameter known as "apns-expiration", which determines
how long time
Apple's push
notification service will queue the
notification to be delivered when the
device is online again.
The "apns-expiration" parameter can be set to 0, which means that it won't be queued at all.
If set to a higher number than 0 that is the number of seconds, the message will be queued.
Finally, the service can choose not to send the parameter at all, or send it as -1 (negative). This means it should be queued for as
long as possible.
The maximium queue time is not infinite, but is chosen by
Apple - and seemingly not documented anywhere. However, PC World described in 2009 that the maximum at that time was 28 days:
https://www.pcworld.com/article/167652/the_limits_of_apples_push_notification_for_the_iphone.html
--jksoegaard”
So it seems the device would have to be off-line for about a month before each push notification gives up. So I’ll assume disabling push notifications is in the phone and thus traceable?