According to the emails that Apple has been sending out, it reads, “There’s been a change to your delivery date. The most current delivery information is shown below. We’ll notify you when your order ships.” For some, they were previously notified that the laptops would be shipping this week, but then the email is now showing a December shipping date instead.
However, it should be noted that this seems to have mostly affected custom orders, also known as Configure to Order. Basically these are orders that deviate from the preconfigured models that Apple has in their store, so if you opted for a different chipset configuration, RAM, or storage, it most likely falls under that category.
What’s strange is that Apple did not warn customers ahead of time before they placed their order that it could be delayed, but either way, if you did pre-order one of the new laptops, you should check your email just to be safe.