But won't this lead to pressure from the authorities on the Trezor team, as it was with Tornado Cash?
No, because Trezor is doing this in partnership with Wasabi wallet.
If regulators are going to make pressure on someone it's probably going to be Wasabi wallet, but coinjoin itself is not illegal in any way.
However, in theory regulators could ban potatoes, meat, milk or anything else related with privacy.