Apple has informed some customers who recently ordered a Mac mini with an M4 chip that has yet to ship that it will be upgrading their order to an equivalent version of the
new Mac mini with an M6 chip at no additional cost.
Apple's email to customers:
Thank you for your recent Mac order. We know you're looking forward to receiving your purchase.
As you may know, Apple recently announced the new Mac mini. Since your order has yet to ship, we automatically upgraded you to the new Mac mini at no addition