I think you're basically correct, but I think the "commercial paper" or "cash equivalents" or whatever they want to call it is loans that originate from the stablecoin issuer, that are against crypto cold wallets of the customer.
There's about 1,000,000 BTC in cold wallets of customers of stablecoins. They prove to the stablecoin issuer that they control the wallet (send two small transactions to some address somewhere). Then the issuer loans them the stablecoin and holds the paper against that debt, denominated in dollars. This provides a service to create liquidity out of BTC cold wallets, which is why it is popular to begin with.
Since the debt is dollar denominated that means if the stablecoin falls to $.50 then they have to pay back half the debt in real USD. So that creates upwards pressure to maintain the PEG. Downwards pressure is easy and just profit taking if it exceeds $1.00
Also explains why Tether printing stops once the outstanding number of Tethers is worth roughly 1,000,000 BTC and BTC pulls back. Once the BTC price falls much lower than that, you start to see redemptions and burn. Then when it rises near that point again you start to see more issuance.
This also answers the question of "who buys Tethers with USD?" Nobody does, it is all crypto debt.
And this all creates a positive feedback cycle driven by debt, backed by crypto. What could go wrong?