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.
New villain is a cleaner with a feather duster +1.
I was legit imaging a pile of dust that learns telepathy to communicate with their party members and screams in an angry scotch accent to be thrown at their enemies so that their particles might sting the bastards eyes and blind them
They’d be deathly afraid of any and all cleaning staff, but also the party would have a broom and catch pan of some sort for when their buddy get a lil spilt