No; ArcMap Server does not fully support map rotation. Map rotation can be set in the data frame properties of an ArcMap document. The map document can then be served via ArcIMS using ArcMap Server. The initial display of an ArcMap Service will properly display the rotated map.
However, information regarding the map's spatial reference in the GET_IMAGE AXL tag does not contain any value for rotation. There is no AXL equivalent for map rotation. The Spatial Server is unaware of any rotation set in the map. Therefore, IMAGE or QUERY requests made to this service will not match the actual spatial reference of the data frame being served. This will lead to inconsistencies when navigating or querying the map.