I think being raised on a paleo diet would make most people shorter - insulin is a growth hormone, and eating high GI processed food like white bread, sugary cereals, and potato fries releases much more insulin, hence people grow taller.  This is why the latest generation is taller than their parents.  Along with all the growth hormones in milk.  If you're eating a paleo diet with no milk past weaning and all low GI foods (except fruit which still can't compete with junk food in the GI charts) then you're not going to grow as tall.  Children who were small for their age on a standard diet would probably grow taller on a paleo diet due to the high level of nutrients, and curing any health problems, and so would end up average height.  However I don't think anyone would grow "tall".  Stoneage people were around 5'5" (women) and 5'9" (men).  They were taller than the early farmers (eating wholegrains so also on low gi diets, which contained far less nutrients) but they weren't tall by modern standards. 

Didn't Weston Price discover that people on traditional diets were broader and shorter, and refined grains and sugar produced people with thinner skeletons who were taller?  The former tended to be all the same height and shape, whereas the latter were all different.  Pottenger's cats also, showed uniformity in size in the healthy group, while the unhealthy group were all different and tended to have overly long back legs. 

Loren Cordain encourages his children to eat potatoes, dried fruit and yams, so as not to disadvantage them heightwise in our modern society, even though he says high glyceamic diets in childhood also increase risk of heart disease in adulthood.