The result handed the Red Bull driver his maiden F1 world title while denying Hamilton a record eighth and led to an international outcry.
The Australian was heavily criticised by Mercedes and by Hamilton, with the seven-time world champion alleging over his team radio that the race result had been "manipulated".
For most of the winter, with Hamilton's own future in the sport up in the air, Masi's position looked to be untenable. But the mood music had shifted slightly in recent weeks with a number of drivers speaking up in support of the Australian and expressing sympathy for him. Masi was even present at Monday's F1 Commission meeting where Ben Sulayem outlined some of the changes the FIA intended to implement.
This did not extend to Masi's future. The Telegraph understands that the Australian held a further meeting with Ben Sulayem on Tuesday in which he allegedly expressed disappointment at the lack of support given to him by motorsport's world governing body.
Whether Ben Sulayem had already determined to make the change, or whether that meeting decided it, Masi is no longer the man calling the shots.
Ben Sulayem said that Niels Wittich and Eduardo Freitas would act "alternately" as race director through this season's 23 races, with Herbie Blash - longstanding right-hand man to Charlie Whiting whose sudden death in the week leading up to the 2019 season-opening Australian Grand Prix led to Masi's arrival - coming in as a permanent senior advisor.
"To assist the race director in the decision-making process, a virtual Race Control room will be created, like the video assistant referee Var, in football," Ben Sulayem said. "It will be positioned in one of the FIA offices as a backup outside the circuit.
"Using a real time connection with the FIA F1 race director, it will help to apply the sporting regulations using the most modern technological tools."
One of the reasons drivers and pundits expressed support for Masi was because of the immense pressure he was placed under in Abu Dhabi, and at races before that, with team principals and managers actually lobbying him in-race. The radio messages were broadcast live on the world feed, which made for riveting television but frequently put the race director in an awkward spot.
Ben Sulayem said teams would still be allowed to contact the race director going forwards, but the messages would no longer be broadcast to the public and would have to be asked "according to a well-defined and non-intrusive process".
There will also be a review of the unlapping process under the safety car by F1's Sporting Advisory Committee. The findings of that review will be presented at the next F1 Commission meeting prior to the start of the season in Bahrain on March 20.
"I presented this complete plan to the members of the World Motor Sport Council and the [FIA] Senate who gave their full support," Ben Sulayem concluded. "With this plan, [the] FIA opens the way for a new step forward for Formula 1 refereeing.
"Without the referees, there is no sport. Respect and support of the referees is in the essence of the FIA. That is why these structural changes are crucial in a context of strong development, and the legitimate expectations of drivers, teams, manufacturers, organisers, and of course, the fans.
"I warmly thank all those who contributed to this reform. These changes will enable us to start the 2022 Formula 1 season in the best conditions, and our sport will be even more loved and respected."
Whether that will be Mercedes and Hamilton's reaction remains to be seen. The 37-year-old is due to speak for the first time since Abu Dhabi at the launch of Mercedes' new challenger on Saturday.
