Hi Mike! Welcome in to the community. When subscribers move lists, their stats would remain in the original list.
When they are moved, the list they are being moved into sees them as a new subscriber and would add them as newly subscribed.
Was there a reason you are moving subscribers between lists? You can use tags and segmentation to have subscribers managed in one list versus multiple and you can then send them content specifically based on what tags they have.
We have a post that gives an example of how you can use tags and segments.