Quipuswap will likely support USDT when it is issued on Tezos. According to the last report, 30 million USDT had been issued. It is unclear how much more has been issued since then, but it is likely that Quipuswap will support it when it is available. Quipuswap is a decentralized exchange that allows users to trade tokens on Tezos, so it is likely that when USDT is issued on Tezos, Quipuswap will support it.