The company concerned with the function is not stating that No Man's Sky used it. They are more curious as to if they did or didn't. Unless the game developers state that they have used this function without license, there should be no concern. Even then, patenting a mathematical function is a gray area unless it was patented specifically for the use of procedural generation, or something as specific.
"We don't want to stop the launch, but if the formula is used we'll need to have a talk." They have no idea if they even used the formula, calm down guys.