I think it's highly likely they considered it. One of Apple's main marketing pieces is security/privacy. It's important as they push into the health and payment

I think it's highly likely they considered it. One of Apple's main marketing pieces is security/privacy. It's important as they push into the health and payment marketplaces (for things like the iWatch and contactless payments). It would make sense they want complete control over their hardware stack end to end. You can even see this in the Apple Secure Enclave on mobile, which was made possible due to their ability to customise their own ARM chips.