In the future all films will be shot at 48 fps or even higher frame rates even by directors who prefer the look of 24 fps. During the final editing directors will judge the aesthetics of each scene and will convert 48 fps to 24 fps if a film look is desired. However when editing the fast action sequences the choice of whether or not to use higher frame rates will receive much higher scrutiny.
They've been able to do that for years now (shoot in higher frame rates). There are many workflow reasons not to do that.