All three had been postponed until an unspecified date because of the coronavirus pandemic.
In their place, MotoGP announced a season-ending race in Europe, at a location to be announced after August 10, for November 2.
The championship will therefore include a total of 15 events, organisers said, instead of the 20 initially planned.
The championship resumed in July and two MotoGP events have already been held at the Jerez circuit in Andalusia.
They were won by Frenchman Fabio Quartararo, who leads the world championship. The next race is scheduled for Brno in the Czech Republic on August 9.
Revised motorcycling world championship calendar:
March 8: Qatar, Moto2 and Moto3 classes only (Losail International Circuit)
July 19: Spain (Jerez-Angel Nieto circuit). With MotoE
July 26: Andalusia (Jerez-Angel Nieto circuit). With MotoE
August 9: Czech Republic (Brno circuit)
August 16: Austria (Red Bull Ring, Spielberg)
August 23: Styria (Red Bull Ring, Spielberg)
September 13: San Marino (Misano Marco Simoncelli circuit). With MotoE
September 20: Emilia-Romagna (Misano Marco Simoncelli circuit). With MotoE
September 27: Catalonia (Barcelona-Catalonia circuit, Montmelo)
October 11: France (Bugatti circuit, Le Mans). With MotoE
October 18: Aragon (MotorLand Aragon, Alcaniz)
October 25: Teruel (MotorLand Aragon, Alcaniz)
November 8: Europe (Ricardo Tormo circuit, Valencia)
November 15: Valencian Community (Ricardo Tormo circuit, Valencia)
November 22: Final race of the championship at a circuit in Europe not yet specified.
Races originally scheduled but cancelled:
Qatar Grand Prix, (MotoGP class only), German Grand Prix, Dutch Grand Prix, Finnish Grand Prix, British Grand Prix, Japanese Grand Prix, Australian Grand Prix, US Grand Prix, Argentine Grand Prix, Thai Grand Prix, Malaysian Grand Prix.