Yes, it looks like 12% of their assets are in commercial paper.
I'm not claiming to be an omniscient source of truth, but USDT is supposed to be backed 1:1, is audited regularly, and has survived extreme volatility events and bank runs for the better part of a decade.
Maybe it will collapse some day. I personally have more trust in USDC and Circle, so I use that if I need a stablecoin.