He's had more than one type of gimmick. He was doing something that oddly enough was somewhat similar to the gimmick Antonio Banks debuted in WWE as. Van Prose debuted stating he was the "MVP of Next Generation Wrestling".
He shouldn't have to change his ring name just because a mainstream promotion debuted a guy with the same gimmick and initials.
I am sure the legal department of the WWE would consider that copyright infringement.
"The most important kind of freedom is to be what you really are. You trade your reality for a role. You trade in your sense for an act. You give up your ability to feel, and in exchange, put on a mask. There can't be any large-scale revolution until theres a personal revolution, on an individual level. It's got to happen inside first." - Jim Morrison
Why SHOULD he change his name? The gimmick was HIS to begin with. If anything, providing that Van Prose did copyright the name, the initials and the gimmick, Van Prose should sue WWE for gimmick infringement.