Formula 1 could suffer through a "chaotic" first season with the all-new regulations beginning in 2022.
"The new rules will result in tougher racing and more fighting," he told Ilta Sanomat newspaper.
However, he admits that it may take some time for that to kick in, as big rule changes in Formula 1 typically result in big performance gaps early on.
"For example, the current gaps are much smaller than a few years ago," said the Frenchman.
"This has been a particularly good season. The competition at the front between Max and Lewis is fierce, and places 6-16 are often separated by only a few tenths."
But it could be a very different story in 2022, Vasseur admits.
"It's always the same story," he argues. "Teams often take different directions in these situations, and someone can gain a really big advantage from it.
"Others then have to react, but in the beginning the situation may be more chaotic."