Large playerbase will join in due to both nostalgia as well as for players never experiencing the game
"from the beginning."
More than 60-70% will leave when they eventually see how "poor" the game will be, both graphically,
engine-wise, and the various sorts of pre-game designed features that no longer exist, I.E. weapon
skills, spell ranks, overpriced everything, the "Hit" stat, etc.
The small playerbase left will still be sizeable enough to merit keeping the server active, but it will
be nowhere near as big as the post-vanilla game will be.