BNR abandoning Objective-C support in iOS development

It’s very discouraging that BNR isn’t releasing any Obj-C resources for iOS 9 and Xcode 7. I understand that Swift is the new hotness, but it’s still undergoing a lot of changes, and Apple has said that Swift 3.0 will have sweeping changes to syntax that will take further effort to transition over. Meanwhile, Obj-C has been around for ages, and is still usable. Why can’t new tutorials support both languages? I know that supporting a legacy language isn’t free, but if Apple can do it, why can’t those who teach Apple’s languages do the same?