They (Intel?) replaced the hardware and software with a better system, called Assistive Context-Aware Toolkit (ACAT). It allowed him to use computer easily (compared to the old system) [0]:
The new Intel user interface operates like an engine. A sensor mounted on Hawking's cheek is detected by an infrared switch attached to his glasses, helping Hawking select a character on his computer. A customized version of the popular SwiftKey app has greatly improved the system's ability to predict his next characters, words and actions so he only has to type the first few characters of a word. That information is relayed to his speech synthesizer.
To search the Web, for example, Hawking previously had to take lengthy routes: Exit from a communication window, navigate a mouse to run the browser, navigate the mouse again to the search bar, and finally type the search text. The new system automates all of these steps seamlessly and quickly.
[0] : https://www.usatoday.com/story/tech/2014/12/02/intel-hawking...