In standard processing, in my home process, it only has underexposure latitude, with 2 stops under being best, 1 stop over is there and scannable but is dense and has a thin density range that needs stretching out.
Point is, its all in the processing
Point is: it's all in the definition of 'minimum exposure'. One must define what the minimum shadow density should be. For someone like me, it's relatively high, because I like lots of shadow detail (landscape). For others, it does not matter much as long as they get any picture at all (news, forensics, etc). Landscape photographers usually rate their films up to 2/3 stops below box speed. To me, XP2 is no different, but standard C41 processing gives it a rather low average gradient. Hence, the exposure latitude towards the highlights and none towards the shadows.