The freezes apply only under direction from the federal government. It's not something that the issuer does without this instruction. Tether has no control of its own here, and Amazon won't either.
There is no incidence of any stablecoin wallet being frozen without the government's order. To do so would invite a lawsuit.
As for what Tether chose to do in the past, that's irrelevant, as the legislation now requires it. The only grandfathered stablecoin that doesn't have freezes is DAI, but it has poor liquidity in comparison.
> Tether may suspend or terminate your access to the Site or any of the Services, freeze any Tether Tokens held by you, or terminate your Tether Token Wallet, as required by applicable Law or where Tether, in its sole discretion, determines it is prudent to do so or where you have violated, breached, or acted in a manner inconsistent with any provision of these Terms or Applicable Law.
They will comply with valid court orders. They can also do it on their own volition.
Amazon is just an example. Dozens are coming.