OK so I just realized another thing. Lemmy Kilmister, David Bowie and Alan Rickman all died from cancer. And all three were ~70 years old. David Bowie had just turned 69, Lemmy Kilmister was 70 and Alan Rickman was a month away from turning 70.
Lemmy abused alcohol and smoked a lot, he totally saw it coming months before. I don't know about the rest. Bowie probably knew too, hence the latest album theme