It's a glaze - it has no abrasive or chemical polishing action. Polish is used more as a term than an accurate product description (its an industry-wide thing).
The interaction between the oils in the glaze and the existing wax may result in the wax being removed but its kinda hard to say. I wouldn't worry too much, though. The glaze will sit on top of the paint, old wax, and whatever else is there. Top that with a fresh coat of wax and you'll be set.
