The smaller arrays are not "left behind" in the garbage sense - the queue will use them again and again in the next rounds. See simulator. Re-use, not Re-cycle - the Garbage-Free Mantra.
If the Queue re-cycles the smaller arrays, it would not be garbage-free anymore.
If you still believe that the smaller arrays should be re-cycled (would be curious why), then comes the technical problem:
Let's imagine a reader stands immediately before reading the array (e.g. to check if the writer has already written). Now the OS preempts him. For how long: We don't know. In the meantime all things in the queue move forward and the program code in some other thread (writer probably) decides to de-allocate the array (and indeed does it).
Now the preempted reader wakes up and the first thing it does is to read from that (deallocated) array ...