Edited translation: "Last year's version has an emotion interface, why did not the latest R5 version have the emotion API?"
The emotion sensing component was not owned by Intel. It was created by a company called Emotient who have now been purchased by Apple. When Apple buys companies, they often stop providing their product to companies that are not Apple. A reason has not been gven for the Emotient emotion component being removed from RealSense but the Apple purchase is likely why it happened.
There are other ways in which emotion can be sensed. In the Unity game engine for example, you can animate objects such as the eyebrows with the face and read whether it is a happy or angry emotion by the angle of the object as it is rotated by the human's face. A downward angle might indicate anger (a downward eyebrow) or an upward angled object might indicate happiness (an upward flexed eyebrow).
Also, the RealSense camera can use infra red to read the heart beat rate of the user with a feature called Pulse Estimation.