I think thats a little misleading as the afterbirth+ DLC has more of a focus on modding, plus the antibirth dlc does not work on top of afterbirth, which makes it a slight downgrade currently. When this DLC works with afterbirth in its entirety then it wont be as misleading.
Fun fact, Edmung (the creator of the binding of isaac game) is trying to reach out to us, in order to give us modding tools to put into antibirth, to give to the public early. So, we might just be actually larger than ab+ in terms of contact AND modding.
But it will most likely not for a while, if ever, be afterbirth compatible.
