In the help file for "Horizontal Charts", it states "Since this might be a labour-consuming task, it is generally recommended to use the PredefinedChartStyle property for overall setup and after that fine-tune the axes and 3D-view if this is required.", which implies that using a PredefinedChartStyle automatically sets the orientation of axis titles.

However, this is not the case. The axis titles are still drawn with the same orientations as they would be for the "standard" vertical chart style.