If Apple price adjustments were due to the adapter, the iPhone 11, XR, and SE would have seen price adjustments back in 2020 when they were first removed. We know Apple doesn't adjust prices after removing accessories.
Apple's exchange rate adjustments are infrequent and typically hedged. The adjustments target to where the market is heading.
We know for a fact the iPad mini 7 costs more today in UK than iPad mini 6. Those prices are explicitly stated in Apple UK press releases. In the U.S, the price hasn't changed from $499.
£479 in 2021
Apple today introduced the powerful new iPad mini with a larger 8.3-inch Liquid Retina display in four gorgeous finishes.
www.apple.com
£499 today
Apple today introduced the new iPad mini, supercharged by the A17 Pro chip and Apple Intelligence.
www.apple.com