Seems like an apt quote; from Apple's point of view, it's much, much better to have Comex helping them increase their security and make it harder for their devices to be jailbroken than for him to be trying to circumvent their security, especially as he's shown himself to be quite effective at circumventing it. Admittedly, we don't don't what he's going to be working on, and his subsequent tweets show an expectation that future versions of iOS will still be jailbroken, so perhaps he's not going to be involved with security (or, just as likely, recognizes that perfect security is impossible).