No. I think it refers to the following:
Removed items are note really removed, but their key set to HI_KEY_REMOVED.
When we copy from oldarray to newarray we filter out the removed items.
When we are in the small --> small case, new array is going to be the internal small array again.
So, as it is going to be the dst of the filtered out thing, we need to make a copy of it first to be able to iterate over the non-filtered items.