Certainly it is neither legally mandated nor very common. As the other commenter pointed out Volkswagen does this. But to be honest if I am not at work my work

Certainly it is neither legally mandated nor very common. As the other commenter pointed out Volkswagen does this. But to be honest if I am not at work my work phone is off/silent and away from my reach anyway, so I don't know if such a rule really would have any impact on me. But this is also because of the surrounding labor laws, which e.g. has mandated and enforced maximum work hours per day, etc.