From his website stallman.org:
Richard Stallman has cancer. Fortunately it is slow-growing and manageable follicular lymphona, so he will probably live many more years nonetheless. But he now has to be even more careful not to catch Covid-19.
Recent video of him speaking at GNU 40 Hacker Meeting. Screenshots of video stream.
Is he accepting medical treatments that require non-free software? Serious question, from what I know of him he would rather die. I don’t know if that changes when you’re actually faced with it though.
Software freedom applies only to hardware you personally own. It wouldn’t even apply to machines you interact with but do not own (such as ATMs or kiosks) since you aren’t the one who agrees to the proprietary software license.
Stallman himself explains it in his computing FAQ.