Yes - by default when any subscription-matching queue is full, the entire message is rejected back to the sender and the message is not enqueued at all.
This behavior can be changed on a per-queue basis, specifically via the Queue Settings > Advanced Settings > Congestion Control > Reject Messages to Sender on Discard dropdown, which has three options: When Queue Enabled (default), Always, and Never.
To allow the broker and other queues to still receive a message when a particular queue is full, you can change this setting to Never.
