McLaren's Lando Norris and Mercedes' Lewis Hamilton completed the top three.
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'.
Sainz was deemed 'wholly to blame' for the first corner collision with Aston Martin's Fernando Alonso, who ended up third, at the final re-start of the triple red-flagged race.
Schumacher, whose Ferrari great father also raced for Mercedes from 2010-12, will attend every Grand Prix as back up for seven-time world champion Lewis Hamilton and George Russell.
Verstappen finished second while seven-time world champion Lewis Hamilton was third.
Mexican Sergio Perez, winner of the previous race in Monaco, was second on the streets of Baku.
Leclerc's car was dominant on the upgraded Albert Park circuit as the Monagesque sealed his fourth career win more than 20 seconds ahead of Red Bull's runner-up Sergio Perez.
The Monegasque, who started from pole, crossed the line 5.5 seconds ahead of Spaniard Sainz.
Velas Network will be creating create digital content for the Ferrari fans.
Team boss Mattia Binotto told reporters that the 22-year-old German would be available to stand in at 11 of the record 23 scheduled races should Charles Leclerc or Carlos Sainz be unavailable.