I see the same effect all the time in fiction. Innovative challenging books don't get published (or even picked up by agents), because the publishing industry is run by the kind of people who are frightened and offended by such books. Which means the audience for those books become only those lucky enough to be exposed to older, denser, more innovative fiction - which invariably shrinks.
He appears to be fine, and just published AnsibleĀ® 471: https://news.ansible.uk/a471.html
It was a different time.