A new announcement from KuCoin was being released earlier and it tackles about the mainnet token swap of QuarkChain. They've promised that they will help all users of this projects to complete the process, and also give an important reminder that they will no longer support the ERC20 QKC token.
https://www.kucoin.com/news/en-kucoin-will-support-the-qkc-mainnet-token-swap