Will FCM Token change periodically like GCM registration ID?

Question

I have published apps in playstore that use GCM and I have a plan to migrate using FCM. everything information i needed have found, but i have one question that not find ans

Answer 1

Similarly to how GCM works, the FCM token can change due to token-rotation.

You can intercept the token rotation implementing the callback: FirebaseInstanceId.onTokenRefresh()

https://firebase.google.com/docs/cloud-messaging/android/client#sample-register

Note: the token rotation is a rare-event. Don't expect to see it often.
But still, if you care about the token you should implement onTokenRefresh() to be informed of changes.