I think he meant the most famous stablecoin out there. There's no doubt about it since the majority of Bitcoin trades are traded in USDT, it even outshines altcoin trades.

Anyway, it's not like it's the end of Bitcoin when people suddenly lose trust on USDT. By far USDT is probably the most suspicious stablecoins out there because of lack of audits and reports on their assets so other predators (other famous stablecoins) will likely try to market their coins to replace the spot of USDT.

I don't think there's going to be any big problem since people have a lot of choices to make. Either use another stablecoin, withdraw their money from exchanges, or use altcoins just like the old days. Sure there's going to be FUD happening that will affect all cryptocurrency (since almost every altcoin is using USDT for trades) but that's only temporary.