I was replying to a post that was saying that changes are bad because they trick players. My point was that mixing and matching to trick the players was part of the game from an early date.But see, that's just it - that WASN'T a change!But people change up this stuff all the time. In fact, original D&D play was based on this sort of thing - eg the GM says "You see something that looks like a beholder" but really it's a gas spore. Or whatever.
Addition and subtraction here are obviously metaphors - but the Planescape changes subtract, because they remove character who are properly understood by Joe Peasant (they're evil fiends of corruption etc) and replaces them with (in effect) aliens who are misunderstood by Joe Peasant.Planescape revealed that Demons and Devils actually call themselves Tanar'ri and Baatezu, respectively, but the material was explicit that your average Joe peasant on some Prime-Material world still calls them Demons and Devils (and probably doesn't know the difference.) While some of these creatures become annoyed at not being referred to by their proper names, a few actually revel in it (such as the Glabrezu in one Planescape adventure who is described as preferring to be called a Demon because many people know and fear that name.) Adding something to the game - such as allowing Dwarves to be Wizards - is not the same as subtracting something from the game