I believe (and have concrete evidence) that Helmut Marko has been given the order by Dietrich Mateschitz to bring the "lost son" Vettel home by 2021 at the latest. Alexander Albon would then switch to AlphaTauri, Daniil Kwjat would lose his racing cockpit.
What would have to happen:
Albon's performance must continue to lag behind that of Max Verstappen. He could have won in Spielberg. But that cannot hide the fact that he is lagging behind from sheer speed.
Secondly: Mateschitz must convince the Thai Yoovidhya family, who own 51 percent of the Red Bull empire, that this would be a good idea.
Third, Vettel has to want it. And he has to have the balls to go after Charles Leclerc and Max Verstappen and take on the next enormously talented youngster teammates.
Then (and only then) is there nothing to stand in the way of a change.
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