Maybe, maybe not. That's just a fairly educated guess I've made. Sorry, I should have made that more clear. Here's a bit more of the evidence I used to come to that conclusion. Lyons Pinball congratulated a "John Conner" on various pinball tournaments \ gatherings throughout the years on their Facebook page. The posts that had John Conner mentioned all had one face in common. The memorial photo they posted shows him without glasses, but so did a couple of the tourney results photos. You can most easily see this with a Google image search of "John Conner Pinball" that turns up a bunch of the Lyons Pinball photos.
https://www.google.com/search?q=john+conner+pinball&source=lnms&tbm=isch
I tried to do further research on their actual website [http://www.lyonspinball.com], but I couldn't get it to load at the time. It does seem to be working intermittently now. Lyons is a pretty good drive from Colorado Springs, which you mentioned as his location. It's likely not that big of an obstacle for a dedicated pinhead's weekly tournament or league meeting though.
You said you hadn't heard back from him in 3 months, which matches the pinside activity of JC_Pins last seen March 14. The memorial photo was posted March 20. If this could be your guy, that time frame certainly matches. I tried searching some local papers (Coloado Springs, Lyons, Longmont, Boulder) for an obituary but couldn't come up with anything in the time I allowed myself.
But it could definitely be a different John Conner in the Denver area that's heavily into pinball that unfortunately passed in the suspected disappearance window.