When I placed my preorder (4/17), Walmart showed estimated delivery date of 5/3-5/4. I received 5/2.Walmart has been a sticky-wicket - order sits with no activity.
In my case, device arrived at my door step the same day it shipped (FedEx facility that received it was less than 60 miles away from me).
Unless in-store stock is plentiful and readily available (pretty iffy with current events), you're likely better off just putting in a backorder and waiting for the item to arrive.