My guess would be to get around Indian import bans on products made outside of India. India has traditionally been very protectionist. It's a large population

My guess would be to get around Indian import bans on products made outside of India. India has traditionally been very protectionist. It's a large population and growing in affluence. So potentially a big new market for Apple. Manufacturing in India would allow them to be seen as a "home choice" there and also provide Apple with a chance to hedge future sanctions on products made in China in other export markets. They can also placate CCP concerns by telling them that they are only manufacturing in India to access that otherwise inaccessible market.