Yep Cortana on my wife's phone used to show her interests, now it just says that feature's not available in your region yet. We're in the U.S. and she's had windows phones since the 520 came out running Windows mobile 8, when Cortana was first introduced :-[
Cortana's dying...... I wonder when the funeral will be? :O
I'm assuming the reduced mobile functionality is b/c of the changes/gutting occurring on desktop where she's become a disjointed, and mostly useless, mess. The mobile stuff stopped working pretty much at the same time 1903 became publically available. Given she's a service, it makes sense the changes to separate her from search and further reduce her "app" abilities are now trickling down to mobile. By the time MS rebuilds her as a pervasive AI assistant, W10M will be long gone.