You experienced a good thing, but what if the exchange delist the meme coins and you can't withdraw it? AFAIK Binance did this for Monero, they suspended Monero withdrawal.
This is also a good point to consider, but on the other hand, unless the exchange is out there, scammers will always send email warnings about tokens that they want to delist and the time that customers have to be able to withdraw their tokens from the exchange.
Like Bitmart Exchange sent me mail about the tokens that they are about to delist this August and the time that customers are allowed to withdraw their coins, it will be very foolish of the person to see such an email and ignore it, unless he is the type that doesn't visit their email on a regular basis.