I have heard this, but changed by whom? Who is the authority that gets to decide on this subject?
This is one of those things where I'm sure some sexologists think the name should be changed and some don't. Although it's more descriptive, it doesn't have a ring to it that will catch on.
There's no dictionary of Proper Sex Terms to Use in the Bedroom, because "g-spot" is slang anyway. It's like saying, "Sexologists have decided that the penis will only be referred to as Dick from now on, never Cock." I don't think people would like that. XD