One basic thing you need to understand is that all 3 of major Chinese smartphone/tablet players (BBK who have Oppo and Vivo brands, Xiaomi and Huawei), as well as Samsung, have people who supply information from each big Apple team. They do not have access to some small projects fully, but have enough data.

Usually 4-5 months prior product release competition not only know all details, they also have sample detailed internal photos, frequently up to 4 physical samples, and also BOM and all supplies list and quotes.

Major attack that can start if US move further will be focused on Aple suppliers and some third party software developers (India, China and exUSSR based). Huawei already approached some exUSSR teams who worked for Apple and they plan to cut Apple completely out of their resources in all three countries. Apple can still retain some of lead developer teams, but with 3x of the previous costs.