According to supply chains, Apple may be expecting higher sales numbers with the iPhone Xr that hasn’t even come to the market. This means that production will have to increase in order to have enough devices to supply the demand.
The iPhone Xr is coming until October and Apple is already increasing their production because they firmly believe that their customers will most likely upgrade to this new and less expensive model. The production is expected to be increased to up to 20 million units in October and the following months. Sure, sales for the current iPhone Xs and Xs Max are doing quite well, but not everyone is willing to buy a $1000+ iPhone. Now, the iPhone Xr is a different story and this lower price with the appearance of the iPhone X will most likely be very successful in sales.