Does the Versys fit him?
Good to have you on the forum, Hawkeye.
I'm not a newbie, but I married one and I've watched her learn to become a safe and effective rider. I think that, if I were in your position, my primary concern would be to find a bike that has the best "fit" - the best height, weight, bar position, footpeg position, center of gravity, etc. - for your son. Of course, you'll want a bike that's not overpowered, that steers lightly and accurately, and that is forgiving of newbie mistakes. I think the Versys fits that description . . . but, as I said already, it's important to be sure that it fits your son's physical proportions and his preferences for riding position. The Versys would have been much too tall of a bike for my wife's first ride.
She started on a Honda Rebel, on which she found it easy to touch the ground (flat-footed) at stops and which was light enough that she could easily keep it upright, steer it at low speeds, paddle-walk it when necessary, etc. I suggest that you and your son visit a variety of dealers so that he can spend time sitting on a wide selection of "starter bikes" and get a feel for the options that are available to him. It would be great if he found that the Versys was "just right," since it is an awesomely functional bike in a very wide variety of riding situations . . . but the greatest thing would be for him to discover the best bike, regardless of brand/model, on which he can develop skill and confidence. Is he going to take some sort of "Basic Rider's Course?" That would give him some valuable instruction and a chance to try out at least a couple kinds of bikes without having to pay for them!
Good luck with your search - and congratulations on being the sort of father who wants to help his 26-year-old son on the road happily and safely. My son is 36 and he learned to ride on the streets in the Marine Corps. We ride together every chance we get. For me, there's no better riding buddy!