If you are looking to pre-order a copy you are in luck! Multiple retailers have been allowing more customers to pre-order the game since it was initially announced. However, finding pre-orders in stock is difficult and it doesn’t seem practical to be checking every retailer day in and day out to see if more pre-orders are available. This is why I recommend signing up for NowInStock account.
What this website does is constantly check the stocks for items at retailers automatically 24/7. For example if you create an account and set an alert for Fallout 4 Pip-Boy Edition, you will get an email to notify you as soon as the website sees that they are accepting more pre-orders. This website can be used for other things too, but this is definitely a huge change to grab yourself a Fallout 4 pre-order.