Apparently not - I was confused about that too at first, but actually working through the tutorial confirmed that this is not the case.

A quick check of the LVM docs reveals that pvmove with no arguments (other than the device) moves all the data on the device to free space in the volume group, wherever it can find it.

It's basically "move this data to anywhere else" as opposed to "move this data to this particular place" which is what we were doing with the previous uses of pvmove.