Yes Plug-in has gone to, here's the email from BMW NA.
"There is a new strategy which now eliminates the in-car video previously supported by the snap-in adapter. A car built after 3/13 that has the 6NR Apps and 6NS smartphone integration no longer has the video option along with the plug in feature which also used the video input... Reason for this is that the iPhone 5 and other smartphones don't offer the video out previously supported by the earlier iPhones."
The potential work around is to put your video files on a USB stick and play from there but I haven't tried that yet.
Obviously your post shows that its not a hardware problem and has simply been coded out.
2014 X3 28i - Deep Sea Blue Metallic - Black 'Nevada' Leather - Brushed Aluminum - Cold Weather - Driver Assistance with Top View - Lighting - Premium - Technology - Satin Aluminum Roof rails - Rear manual side window shades