Dear Bhante Nyanatusita,

> Is it said anywhere that devas can expire before the end of
>their normal lifespan?

I recently came across a discussion of this in the Dhammapada.t.thakathaa in the Udenavatthu. If you have the PTS edition it's on page 173, in Simon Hewavitarne on page 87 of vol I. It starts:

Devalokato hi devaputto aayu-kkhayena puñña-kkhayena aahaara-kkhaayena kopenaa ti catuuhi kaara.nehi cavanti.

The explanations follow. aahaara-kkhaayena is a bit humorous: a deva who is too absorbed in sensual pleasures forgets to eat and dies of exhaustion!

best regards,

/Rett