I can't imagine Apple offering this option -- it doesn't really align with their strengths (privacy first) and weaknesses (data centers). They'd need to fix so much of iCloud first.
> If you're using OS X Yosemite or later, you can choose to use your iCloud account to unlock your disk and reset your password
> If you're using OS X Mavericks, you can choose to store a FileVault recovery key with Apple by providing the questions and answers to three security questions. Choose answers that you're sure to remember
> If you don't want to use iCloud FileVault recovery, you can create a local recovery key. Keep the letters and numbers of the key somewhere safe—other than on your encrypted startup disk
Take a look at this blackhat talk from Apple's head of security Ivan Krstic, where he explains the mechanism they use to secure credentials stored in the cloud: https://youtu.be/BLGFriOKz6U?t=22m31s
