But we don't know yet whether Trezor run their own CoinJoin coordinator server or simply use Wasabi's coordinator.
Why would they partner with Wasabi if they were planning to run their own coordinator? The Trezor team are more than capable of building their own coinjoin implementation and integrating it with Trezor Suite without Wasabi's help. The only reason I can see for the partnership is to give Trezor users direct access to Wasabi's liquidity, but that comes with all the downsides of using Wasabi's coordinator.
You made good point. But it's possible it's limited to technological partnership, where Trezor want to earn additional money by charging fee on their own coordinator.