Could be he isn't well.
We graduated from the same High School. Our class had a 55th reunion this summer and he didn't show up for it. His past attendance at our reunions has been hit and miss, so I wouldn't overstate his absence.
On the other hand, he is in his early 70's.
I don't wish him any bad luck, but I really don't miss his articles. They've been consistently negative and short on research for a very long time.