A long press is a function of time:
"How long has the user pressed?"
3D Touch is a function of pressure:
"How hard has the user pressed?"
In practice, things that your application previously accomplished with long presses may be more suitably accomplished with 3D Touch — things like contextual menus or shortcuts come to mind. Additionally, iOS has new APIs for presenting content using 3D Touch. The article briefly references them.
It appears that a Chinese company named Kunlun licensed IP from Rovio and is developing Angry Birds apps specifically for the Chinese market. Perhaps they're also distributing the app themselves.
Can you imagine the damage done to Rovio's credibility, simply because their licensee got hit? The news sites only talk about "You should delete Angry Birds 2". Nobody ever mentions or explains this third party.
3D Touch is a function of pressure: "How hard has the user pressed?"
In practice, things that your application previously accomplished with long presses may be more suitably accomplished with 3D Touch — things like contextual menus or shortcuts come to mind. Additionally, iOS has new APIs for presenting content using 3D Touch. The article briefly references them.