Map data is nothing but facts, so "copyright does not protect facts" is a strict superset of "copyright does not protect map data". A map is not just the facts it expresses--the map data--but a visual rendition of those facts, which may or may not comprise an original expression. It is the original, creative expression which qualifies a work for copyright privilege, regardless of the form of the work. Original expressions of facts, including the more creative maps, are within the domain of copyright; the facts they express are not.
I would further argue that a programmatically-rendered map is no more original than the raw data it was made from, and consequently should not qualify for copyright either. Certainly a fresh rendition of the map data is not actually a copy of any other map, even if they happen to be identical.