Let's say a person is on vacation and doesn't worry about anything and doesn't read the news. And at this time, the exchange where he keeps Monero is delisting Monero. And time passes, the user visits the exchange - and what happens with his amounts on exchange that was be in Monero?
I know a lot of users on Poloniex are unhappy with how their money is lost and they cannot trade or withdraw because the cryptocurrency is delisted. And the times between delisting and warning of delisting are relatively short, as users claim, so it all seems like on purpose. I heard many people threatening legal action because of this but I have not yet heard of a single court win or that they got their crypto out of the exchange. In fact, many of them say that support is either ignoring them or giving them unhelpful answers.
So I guess if an exchange delists a crypto, and you do not get it out in time
, then you will not get it back.