Unlikely. USDT only accounts for about 2G$ in market cap. Compare this to BTC which is about 150G$ post correction. Even if all of USDT was liquidated completely into bitcoin, then it would shift the BTC price by at MOST 1.3%. USDT is also used to short other big coins such as ETH so we are likely looking at less than a 1% price action on BTC for USDT.