E,
Most of 'em I see growing out in the open tend to have a more spreading 'orchard' tree habit of growth, while those growing in high-stem-density settings do tend to upright, almost a timber-type of growth habit - have some here that are now on the edge of the woods, after removal of 35-40 yr old planted pines that are tall, straight trees with no branches for the first 30 ft or so.

They do tend to 'self-prune'; as lower branches are shaded by the developing canopy, they die off and are shed.

'nother consideration - many grafted selections tend not to have the strong apical dominance present in most seedlings - they've already grown through their 'juvenile' phase, and graftwood taken from mature, bearing trees is less likely to produce an upright 'timber'-type tree.
Think about citrus grafted with 'old budline' scionwood - they tend to be a spreading 'orchard' type tree, as opposed to the upright (and thorny!) growth habit of seedlings.
Good for fruit production, but less desirable for cultivars selected for timber/veneer production - which may require more corrective/training pruning to foster that desirable 'clear bole' furniture/gunstock makers/woodcarvers prefer.

CF,

Cliff England has Claypool H-120 persimmon with roundish canopy. nuttrees.net

Tony