It's because government are putting pressures on exchanges to de-list privacy coins such as Monero.
This has been on-going at the start of 2018, if I'm not mistaken. As we all know, South Korea has a very strict implementation with regards to their exchanges. So it's just a matter of time before we can see Monero being de-listed by a lot of top tier exchanges in the future.
If the government is the reason for delisting a privacy coin it is not really good for privacy coin holders and traders but I guess it is delisted on few exchanges only. I have checked on Huobi Global it is still listed. ZEC or ZCASH is privacy coin too and it is not delisted on Houbi Korea. I'm confused about what is the basis of the Korean government.