The last Hassan al-Nasrallah rumor I ran here was Haifa Wehbe's denial that she'd once been married to the Hizbullah Secretary-General, or as one great headline put it, "‘I didn’t marry Hezbollah’s leader,’ Lebanese sex-icon says."
Extremely fundamentalist Shi‘ite cleric that he is, I'm sure Nasrallah would have take a "death before dishonor" approach to those rumors, given Haifa Wehbe's low-cut dresses and tendencies for certain parts of her to pop out while cameras are rolling. But the latest round of rumors suggest Nasrallah is in ill health. Hizbullah denies them all, insisting he's OK and still in Lebanon, but the rumors, most of which have shown up in the Israeli and/or Turkish press, say he (choose one or more) 1) was flown to Iran suffering from cancer, for treatment; 2) was flown to Iran for treatment of wounds received in an attack by Syrian rebels; 3) is dead of either of the above or something else.
The surest way to prove you're not dying or dead would seem to be a public appearance. Of course he never provided proof he wasn't married to Haifa Wehbe, but ... no. I don't think he needed to. But a public appearance seems essential right now.