I started out on a SL100, yeah I'm that old. Back when I dreamed of owning an Elsinore (but never got)I’m really back and forth about the clutch vs automatic. I think the automatic will let him focus more on balance, anticipating turns, dips, and hills. Allow him to focus more on the riding because shifting will be much easier. But I also get the point of teaching him how to use the clutch from day one. Unfurtunately their isn’t a manual clutch bike his size at the moment where we are riding for him to try out
Worked my up to the XR600 before I quit riding.
Never owned an auto shift other than my 4wheeler Rubicon
IMHO it would be too easy for him to pin the throttle, it keeps shifting and going maybe faster than he's ready for
Get something with a clutch, he'll figure it out soon enough and it may keep him in a slower gear longer
If he's like (I assume) most the people in this thread, he'll be shifting without a clutch before long anyway, just using it as an Oh Shit lever (index finger always over the top)
Good luck and safety first