London-based Enyo Law said Brazilian Massa, now 42, had been 'the victim of a conspiracy committed by individuals at the highest level of F1 together with the FIA and Formula One Management'.
The changes mean Friday's qualifying, which follows an hour-long opening practice session, will set the grid for Sunday's main Grand Prix instead of the Saturday sprint.
The outcome meant Red Bull's titles were safe. The team have won the 2021 and 2022 drivers' championships with Max Verstappen as well as this year's constructors' crown, their first since 2013.
Mazepin, son of a billionaire who made his fortune in fertiliser, had apologised on Twitter for his "inappropriate behaviour" and the fact that the video was posted.
Thirteen-year-old Aashi has been selected along with 19 others in the age group of 12-16 out of 70 entries from five continents.