The new world champion has signed a new long-term deal with the pacesetting team but he also recently coveted moves to Ferrari or Mercedes.
Austrian billionaire Mateschitz said an exit-clause is a "formality, but it is hardly necessary".
"If we cannot give Sebastian Vettel what he needs and he asks us – despite his contract – to let him go, I can not imagine that we would not agree," he told the Frankfurter Allgemeine Sonntagszeiting on Sunday.
Mateschitz also denied that Vettel's new deal is particularly sweet, for example with regards to the demands for PR appearances.
"His PR appointments have been within limits already in the past, so it will not change in the future," he said.
Mateschitz said he is not worried about losing Vettel any time soon.
"There is probably no top team from whom Sebastian has not received any offer, so it is wrong to think he wants to go and only we want to keep him," he insisted.