When I see an official policy from Apple, I will believe it.
Otherwise, is is Internet BS.
Just my opinion.
So far, exactly ONE uncorroborated posting. Could be one particular person at one particular Apple store, for all we know (and that's my guess. Might be a few of them, but a few cases does not a corporate policy make.
"But...but...but I read it on the internets!!! IT MUST BE TRUE!!!!"
I'll wait for the official policy too. That said, having worked on dozens of cigarette-smoke-damaged stinky computers over the years myself, I wouldn't be too surprised if a policy existed about severe chemical or particulate damage -- that's essentially abuse. Same if in a salt-water environment, or an industrial environment with corrosive chemicals in the air.
I've worked on those -- the record holder was one where the air had acidic vapors... The workers had masks of course, but the process control computer, not so lucky. The circuit board, components, traces, etc. had been etched away over time, until one day it stopped working. Total loss, of course.