I too hope this chap is ok.
Do not underestimate the possibility he's just done a flit. It's a very strange hobby in this regard and, experience over 25 years, has told me that there is some strange behaviour that some people exhibit.
I can count at least three long term players I have played with over the years who I'd developed really good, close friendships with. Then, poof, gone. Never heard from again. No "I'm gonna take a break". No "I have some issues". No "you're a twat Mayers". Nothing. Nada. And I know for a fact all three remain healthy to this day.
There are others who I played to a lesser extent then disappeared. I don't consider myself an arsehole to play. I have a laugh. I don't think I particularly do anything that would piss someone off so much that they would just 'break contact'.
It's weird behaviour. Not the way I would treat someone. And, I've gotta admit, it's a little bit upsetting and annoying in equal measure if I'm honest. Just, like, if you can't play anymore, or don't want to play me, f'king tell me