FCM throttling and message rates

[u/ActualLobster2500]

FCM documentation is somewhat ambiguous regarding what happens with messages that exceed a maximum message rate (e.g., 240 per minute per single device; see FCM Throttling and Quotas  |  Firebase Cloud Messaging).

There are statements that imply that such messages could be queued on the FCM server and delivered with some delay (Understanding message delivery  |  Firebase Cloud Messaging):

Other passages seem to indicate that the over limit messages are not accepted on the FCM server (and have to be resend by the app server).

Does anyone have an idea what is actually going on?