I must insist, because it's not just about my perception (I'm neutral about drugs, for I respect bodily autonomy) but the average person.
Even with the recent changes, a history of drug use has a negative connotation. Weed is minor bad, cocaine is bigger bad (except in finance, but that's another story).
By suggesting that MJF disease was fueled by his drug habit:
- you will be causing more people to see him with a negative light
- you might impede what seems to be his good will effort to put his money and fame against the disease
There is no perfect solution, but I think we should at least be aware of these second order effects -- see also The Dark Knight for when Batman decides that preserving the previous good reputation of Double Face was more important, because it gave hope to people.
My personal take: Disease do not come from doing "good" or "bad" deeds - they just are. As someone else said, even if it was 100% due to drugs, that does not precludes compassion.
Also, even if I'm neutral on drugs, lots of people aren't. Therefore, making this connection, while technically true, may bring very little upsides but lots of downsides, so it's better not to, if only because we should leave MJF himself decide what to disclose or not, while by default extending the benefit of doubt.