This follow a point of interest concept can already be achieved using alternative apps, if you have the controller on the combine you can do it with the Go app now.
I'm not convinced there will be a Phantom 4 until later in the year. They do like to tease with rumours of some new product and it often turns out to be something unexpected like the Osmo thing or a different shaped mounting bracket on a new and improved controller.
The trick works because lots of free publicity - so they pull in new buyers anyway.