Masi was given a new position within the company, according to FIA president Mohammed ben Sulayem, who made the announcement in February.
Sebastian Vettel and Kevin Magnussen also agree with Tsunoda that the new race directors lack Michael Masi's experience.
Peter Bayer became FIA's secretary general in 2017, his responsibilities include directing all operations in the sports department.
Masi's future was a major topic of discussion throughout the off-season, following the contentious decision-making in Abu Dhabi.
Michael Masi was removed from his post by the FIA after his controversial call which afforded Verstappen the chance to beat Hamilton.
Horner also believes that the former race director received insufficient support, and he wished him the best of luck.
Max Verstappen says decisions made under pressure and with outsiders exerting influence makes it only natural that not everybody will agree.
Masi will be replaced by Eduardo Freitas and Niels Wittich, and a series of new structures, including a stand-alone race control unit.
The FIA presented a report on the Abu Dhabi GP to F1 teams. However, they only issued a small statement on the same publicly.
Vettel, who is also a director of the Grand Prix Drivers' Association, has thrown his support behind the embattled Australian.