The most recent estimate  I could quickly find valued the iPhone X at $600 in components alone (excluding assembly), so any trade war would seem to still be incredibly perilous for Apple, especially on their lower-end products.
I haven’t been following any of this, so perhaps they covered it in another story, but for Bloomberg I really expected a bit more of an in-depth analysis.
Outsourcing to India will follow the same trend as other Chinese OEMs doing final assembly in India to circumvent 20% import tariff on phones. Most of the materials are still going to be procured from Chinese supply chains.
Pretty sure this list would count tsmc as a Chinese company.
Edit: To add, China's strength is both logistics and the ability to setup new production processes. Mature processes for old phones can be moved to India for production, but major hardware changes in new sku is still only viable in China because only China has the expertise, logistics, capacity to rapidly iterate and trouble shoot new products.
Even if some details or price estimates are wrong, the fact that they are dependent upon a third party for the most expensive component with no obvious alternative is a problem.
Apple tends to have multiple display providers, even for the same phone model (Sharp, LG, Samsung). They are on top of that problem, mostly.
That is only for LCD. Not for OLED, they are only from Samsung.
For example, I was astonished when a $1000 IHS report called iPhone 4 battery at ~$10 when the retail price of a replacement is less than that.
iPhone 3 was certainly around just $30 to $40 dollars in cost, but after that, the "arms race" began.
At around iPhone 4 era, all big makers began putting more and more custom and direct sourced components, and estimating costs got much harder.
Basically, these estimates seem like wild guesses.