I was a little puzzled by what seemed like sort of a "knee-jerk" reaction to try to contact the other person. I'm not saying I'm against that, but normally when I want to contact somebody in a situation like this it's to try to find out how they're related, and maybe to invite them onto GEDmatch. Both those goals are already met, and it's quite a blessing!
Certainly there are things he could talk about with this match - collaboration on common research, an invite to WikiTree, etc - but this seemed like a DNA discussion, and he already has all the essentials without this person being involved any further. His time might be better spent trying to identify OTHER matches, for example. Maybe find a 3C on this or another line, for example.