Disclaimer: this is purposefully obtuse.
Other effects in the game which explicitly state they kill you:
Shadows, succubi, massive damage, death saving throws, beholder death ray (notably not even their disintegration ray kills you), power word kill, vampires, mind flayers, night hags, drow inquisitors.
Clearly, if they intended for disintegration to kill you, they’d have said so. Since specific overrides general, and there is no general rule that disintegrated creatures are dead, I rest my case. QED.
This is straight up horrible. LOL, party goes on a mission to obtain a cure for petrification to save a bunch of statues only to discover that they are all a bunch of corpses because the villain is just that big of an asshole.
Hope you brought your diamond dust!