A partner testing yesterday observed that clicking on an external link does not trigger any action. This should bring up the exit interstitial, but no activity occurs. I tested on an iPhone 6s running iOS 9.2.1 (current) with the standard safari browser. I also removed the override for the exit interstitial "Continue and do not warn again" button with the associated URL, and this had no effect on the problem. I also verified this occurs both on m-dot and zero-dot subdomains.
Something must have changed in MobileFrontend, but I don't remember seeing anything around this. Here's the error, I'll look into fixing it.
TypeError: ContentOverlay.extend is not a function TypeError: ContentOverlay.extend is not a function