According to a report from Nikkei Asia, it seems that Apple is apparently using components from its iPads for the iPhone 13. It has been reported that both devices actually do share some common core and peripheral components, which means that Apple can use certain parts interchangeably.
In fact, the report claims that as a result, production of the iPad has been down 50% from Apple’s original plans for the past two months, where it seems that the company is “saving” the components for use in the iPhone 13. Apple apparently foresees a stronger demand for the iPhone 13 which is why they are making this decision.
This is also apparently not Apple’s first time “sacrificing” iPads for the iPhone. The last time they did it was last year for the iPhone 12 during the pandemic, and assuming this report is accurate, it looks like they’re repeating last year’s practices again.