CustomNameVisible not working with mobs!

This bug is connected to "fixed" bug MC-57516

In 1.7 CustomNameVisible was working for all entities. In 14w21b too. But in 14w25a bug MC-57516 appeared.
In 14w29a Searge fixed this bug, but only for non-mob entities!

"The CustomNameVisible tag does not work on animals and mobs, because they have different rules about showing the name. For the other entities it should work." -Searge

But that is a bug! It was a good, working feature previously and then it was removed!