I think you've misread something. First things first, the links you've mentioned talk about the exit nodes (which are your "way out" to the clearnet). Wasabi utilizes hidden services, that means, no exit nodes intervene.
Yes, I grabbed the wrong links I'm mobile / remote at the moment.
But you are still passing information to hidden services in clear text. The links I wanted to grab discussed that sending things in the clear was now creating a need to trust the person getting the data (in this case wasabi but they were discussing ahem...other things) and the person running the last hop that service was connecting to which 99% of the time was the service itself.
Might not be making myself 100% clear here but the best way to say it is that since the wasabi coordinator itself is getting the info in cleartext unless they are running their onion services on the same server then somewhere even if it's just between Virtual Machine 1 and Virtual Machine 2 on the same physical hardware blade there is still data being unencrypted data being passed. Is it a 'real' threat? Depends on how they are doing things.
In the end, probably not important since you are trusting them to do things they way they say they are doing them anyway.
-Dave