apple news app portrait mode only?

Why? No one here on this user to user only forum works for Apple. The only answer we can provide is Apple didn't design the app to display in landscape. You can provide feedback to Apple via this link to let them know you'd like to be able to read the app in Landscape --> Feedback - iPhone - Apple

There is no way to trick something hard coded into iOS. The ability for an app to display in landscape, MUST be hard coded in the app. And since this is an actual Apple app, there is no way to work around that.