Well, Apple’s historical stance when it comes to court orders that require them to release Apple-signed software containing a backdoor has been to:
- Refuse even though they are legally required
- When the government complains they are refusing to follow through with a legal order, they bury the government in lawyers because they have more money than god
So, I think it’s probably reasonable to think Apple devices will not suffer from this particular problem. When it comes to the operating system there is not a particularly good way for them to target a specific user without jeopardizing all other users, which Apple has not done before.
Individual developers of apps from the App Store, on the other hand, could certainly pose a threat. Additionally, I would not fully trust iCloud where Apple could more easily target a specific customer, although I personally would deem that highly unlikely, especially if using Advanced Data Protection.