I saw that he was sick earlier this month when there was an appeal for cards:

According to Pentagram partner Michael Bierut, "Luca said that Massimo would be thrilled to get notes of good wishes from people whom he's touched or influenced - whether personally or remotely - over the years. Luca has visions of huge mail bags full of letters. I know that one of Massimo's biggest fantasies has been to attend his own funeral. This will be the next best thing. Pass the word."

Not sure how that turned out but this request was pretty widely reflagged.