I think that the flow of new tracks and time hanging around the top of new items list is a more or less constant speed as there are a set number of reviewers who can only review at a certain speed, irrespective of how many tracks are in the never ending queue.
It’s not like the end of the queue is ever reached and then the last new tracks hang around around at the top of the new items list until more arrive.
The only thing that will change in all of this is the length of the review queue time.