Not that I think this is a bad change, but it strikes me as funny that Fed rulemakers give "accessibility" as the reason for their pitching rules, yet follow NCAA with almost every change except starting with both feet on the pitching plate.
Practically speaking, this changes almost nothing, except it is now explicitly legal to have just the pivot foot heel bone in contact with the front vertical edge of the plate, or some other situation where the foot is not on top.