“Everything not saved will be lost forever” - Nintendo Cartridge. Somehow we block out poetry in our own language, but translation it can pass through as a translation.

Without context, it's still a reasonable translation. I guess the idiomatic English in that situation would be "When the coffee is gone, it's gone.", or maybe "Refills of coffee will not be provided".

I’d love to see the original setting. Was the sign intended to tell the consumer that no fresh coffee would be made, or that there are no free refills? The museum setting (in front of an empty coffee maker) implies the first, but I suspect the second was intended?

It says, when this coffee has run out, it is finished.

Basically, this pot will not be refilled. I can imagine at a hotel where there is free coffee in the lobby but just in the morning.

It’s the coffee-pot equivalent of “while supplies last”.

A haïku to leave before seppuku. No more coffee is indeed catastrophic.

Reminds me of the out of coffee scene from Airplane 2.

https://www.youtube.com/watch?v=Bbv5B71KmkA

Honestly, the only mistranslation here is the extraneous full stop after the first clause. Replace it with a comma and it becomes a serviceable, if odd-sounding, English sentence that conveys the correct meaning.