This is a term used to cover a wide and indiscriminate range of information maps.
City street maps, maps in an atlas, hiking trail maps, survey maps, and many others related to geographical location, all are “visual”. And yet these are rarely (if ever) meant when the term “Visual maps” is used. It is really hard to find maps that are not visual. Embossed maps for the visually impaired, perhaps, and metaphorical uses of the term, like mental map. But move that phrase into Spanish (mappas mentales) or French (carte mentale) and you’re back with mind maps, anyway.
So not only does the word “visual” add nothing to “map”, but the term covers maps that are not generally intended when people refer to visual maps.
WikIT uses terms such as “Visual thinking” and “Information maps” when a general term is needed.