Ive heard others make the same claim. It makes sense to me from what Ive seen of others with a serious, terminal cancer diagnosis. McLame is running a scam.
I'm thinking it's touch and go if he makes it to May 21st which is the deadline if a Special election will be required to replace him, or his seat is appointed through the remainder of his term.
https://arizonadailyindependent.com/2018/03/05/mccain-tweet-shows-frail-condition/